N-3NSPI (CA) RIR-1 to 18 - Redacted
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NON-CONFIDENTIAL 1 Request IR-1: 2 3 Reference: "This project was identified as a high priority within NS Power's dam safety risk 4 prioritization due to the deteriorated condition of the concrete structures and the stability 5 deficiencie...
AI summary The response confirms that the refurbishment of the Ruth Falls Main Dam began in 2019 with the procurement of rubber dams and vertical lift gates, but construction was delayed until July 2025 due to the lack of required environmental permits.
SECTIO ECTION A (FOR ALL APPLICATIONS) ALL INFORMATION MUST BE PROVIDED: Calculations for sizing of structure, including but not limited to watershed area (1:100 yr return event for
AI summary The text outlines a section requiring detailed calculations for the sizing of a structure, specifically mentioning the need to consider a 1:100 year return event for watershed area. The context suggests this is part of a regulatory application process.
PROJECT OVERVIEW NSPI is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2020. This work is necessary in order to address structural and freeboard deficiencie...
AI summary NSPI proposes refurbishing the Ruth Falls Dam to address structural issues and meet safety guidelines. The project includes replacing stop log bays, installing a spillway, and modifying the dam's structure. Fish conveyance systems will be used to ensure fish movement during construction, which is expected to take six months starting in May 2020.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam involves replacing concrete structures with rubber dams and installing new spillway systems, while ensuring fish passage is maintained during construction. The project includes temporary water level reductions and the installation of temporary barriers.
2.2 Proposed Refurbishment Activities The proposed maintenance activities are as follows: - installation of fish conveyance system near the entrance of the fish ladder; - lowering of Ruth Falls reservoir approximately 7‐15 feet; the actual...
AI summary The proposed refurbishment activities include the installation of fish conveyance systems, reservoir lowering, dewatering, concrete refacing, and the installation of new spillway and sluiceway components at Ruth Falls. These activities aim to improve fish passage, maintain proper water flow, and upgrade infrastructure.
4.5 Rehabilitation Following any excavation and placement activities, areas disturbed by machinery or equipment will be returned to pre‐construction condition. Any exposed soil areas will be stabilized to prevent erosion. In the event that...
AI summary This section outlines the requirements for rehabilitating areas disturbed during construction, including stabilizing exposed soil and taking temporary measures if long-term erosion issues arise.
5.0 ARCHAEOLOGICAL CONSIDERATIONS An Archaeological Screening and Reconnaissance (ARIA) for the Ruth Falls Headpond was completed in 2017. The purpose of the ARIA was to assess the potential for archaeological resources in the project area...
AI summary An archaeological screening and shovel testing were conducted for the Ruth Falls Headpond project. The screening identified three areas with high potential for archaeological resources, but shovel testing in two of these areas found no significant resources, allowing development to proceed.
CI 50518 CA IR-5 Attachment 1 Page 19 of 35 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description providing six project updates, the project was deferred t...
AI summary The Ruth Falls Dam Refurbishment Project was deferred to 2019 as NS Power reviewed design options. Updates were provided to KMKNO through meetings and monthly communications, with construction planned for May to November 2020.
NSPI Response: NPSI does not develop the detailed construction schedule as this is completed by the contractor after award of the contract. NSPI has provided a tentative high level schedule of the work as part of the application. Detailed...
AI summary NSPI does not create detailed construction schedules, as contractors handle this after contract award. A high-level schedule is provided, with dewatering starting in early to mid-May and refilling beginning between late October and mid-November.
CI 50518 CA IR-5 Attachment 3 Page 4 of 17 REDACTED (CONFIDENTIAL INFORMATION REMOVED) February 27, 2020 Grant Brown The required 35 cfs maintenance flow will be maintained throughout the construction works via the stoplog sluice bays. The...
AI summary The document discusses the installation of sluice gates and temporary access roads during construction works, emphasizing the maintenance of a 35 cfs flow to ensure fish passage. No cofferdam will be installed upstream, and the contractor will determine the location and design of the access road.
CI 50518 CA IR-5 Attachment 3 Page 5 of 17 REDACTED (CONFIDENTIAL INFORMATION REMOVED) February 27, 2020 Grant Brown temporary access road may be required, currently consists of exposed bedrock and boulders. Typically, temporary access roa...
AI summary The document outlines construction plans for a temporary access road and dewatering of the Ruth Falls Reservoir to allow fish spawning. It details materials, safety protocols, and environmental protections to be followed during the project, including handling of hazardous materials and oil spill contingency plans.
THIRTY PERCENT DRAWING PACKAGE The thirty percent complete drawing package provided in June of 2018 is an accurate representation of the modifications planned for the Ruth Falls dam. The subsequent planned submittals will add details for c...
AI summary The thirty percent drawing package for the Ruth Falls dam modification project is considered accurate and sufficient for communicating the planned design. Further details will be added in subsequent submittals, but the overall design plan will remain unchanged until a contractor is selected and reviews the package.
100-01 REFERENCE DESCRIPTION [A X,X,X,X X X,X,X X,X X,X X,X,X SEAL DEPARTMENTA L APPROVALS SCALE Nova Scotia PM CIVIL E & I POWER An Emera Company energy everywhere. 1:52 месн CONST RUTH FALLS 8 DRAWN TECH RUTH FALLS REFURBISHMENT PRJECT 8...
AI summary The text appears to be a table or drawing reference list related to a construction or refurbishment project, including details such as scale, approvals, and technical drawings. It includes the name 'RUTH FALLS' and references to 'REFURBISHMENT PRJECT' and 'DRAWN TECH'.
RE: Application # 2019-2638165-00 With reference to your application please be advised that as a result of an initial review, your application has been deemed incomplete. As a result, Nova Scotia Environment (NSE) is requesting the followi...
AI summary Nova Scotia Environment has deemed an application incomplete and requested additional information, including detailed design drawings, considerations for construction completion amid potential impacts from COVID-19, a detailed water management plan, and descriptions of how high flow scenarios will be managed, particularly regarding erosion and sediment control.
CI 50518 CA IR-5 Attachment 5 Page 2 of 160 REDACTED (CONFIDENTIAL INFORMATION REMOVED) June 22, 2020 Grant Brown 3. Provide a detailed water management plan including: construction staging including cofferdam placement and dewatering and...
AI summary The document requests a detailed water management plan, including construction staging, dewatering, flow maintenance, contingency plans for high precipitation, and erosion and sediment control, to be prepared by a qualified professional engineer licensed in Nova Scotia.
NSPI Response: The reservoir will be lowered primarily through generation. Water will flow through the power canal to the generating station until the reservoir level reaches the level of the intake. While the generating station is online,...
AI summary NSPI outlines the process for lowering the reservoir through generation and controlled removal of stop logs, emphasizing monitoring for environmental impacts and downstream flow management during the drawdown.
CI 50518 CA IR-5 Attachment 5 Page 6 of 160 REDACTED (CONFIDENTIAL INFORMATION REMOVED) June 22, 2020 Grant Brown field survey of riparian vegetation for rare plants and wetlands on the Ruth Falls Headpond was completed by Jacques Whitford...
AI summary A field survey of riparian vegetation and wetlands around the Ruth Falls reservoir was conducted in 2007. The reservoir will not be lowered below a specific level during construction, and a variance request will be submitted to NSE for any necessary drawdowns.
1.2 Study Scope The intent of the Study was to identify wetland and potential rare species habitat located within the vicinity of the dam and generating station (the Study area) in preparation for further capital works projects. Wetland de...
AI summary The Study aimed to identify wetlands and potential rare species habitats near the dam and generating station to support future capital works projects. Wetland delineation and functional assessments were conducted at all identified wetlands.
CI 50518 CA IR-5 Attachment 6 Page 1 of 3 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 30 Damascus Road, Suite 115 Bedford, NS Canada B4A 0C1 902-424-7773 T 902-424-0597 F www.novascotia.ca Our File Number: 95100-30-BED-2019-2638165 March 3...
AI summary Nova Scotia Power's application for the Sheet Harbour Hydro System – Ruth Falls Dam Refurbishment has been deemed incomplete due to missing information. The Department of Environment and Climate Change (ECC) has requested detailed design drawings, updated construction schedules, and a comprehensive water management plan from qualified professionals. The application must address environmental concerns and provide clear details on construction stages and mitigation measures.
2. What Considerations and contingencies will be available to NS Power to ensure construction completion in November given the potential impacts from COVID-19? NS Power has provided a revised construction schedule in Section 2.2. NS Power...
AI summary NS Power has requested a delayed construction start and completion date for a project due to considerations such as upstream alewife migration, fish spawning windows, and potential impacts from COVID-19. They have implemented safety protocols and successfully managed projects under pandemic restrictions in 2020.
CI 50518 CA IR-5 Attachment 7 Page 4 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3. Provide a detailed water management plan including: construction staging including cofferdam placement and dewatering and maintenance of flows, cont...
AI summary The document requests a detailed water management plan for a project, including construction staging, erosion and sediment control, and contingency planning for high precipitation events. It also asks for confirmation on the water management approach, potential downstream risks, and a methodology for water quality monitoring during and after construction.
2.1 Proposed Construction Activities The following construction activities are proposed for the Project: - 1. Lowering of Ruth Falls Headpond from full supply level (FSL) of elevation 109.4 ft (33.3 m) to elevation 98.0 ft (29.9 m). The ma...
AI summary The proposed construction activities for the Project include lowering the Ruth Falls Headpond, installation of temporary cofferdams and access paths, notching out a section of the dam for a bypass, and removal of existing stoplogs and walkways. These activities aim to facilitate water management and ensure fish protection during construction.
CI 50518 CA IR-5 Attachment 7 Page 6 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - 8. Installation of stoplogs/other metal sheeting in existing deep stoplog bays will be undertaken to isolate the existing sluiceway section. - 9. Ref...
AI summary NS Power outlines plans for infrastructure upgrades at Ruth Falls, including installation of sluice gates, refurbishment of the sluiceway, and construction of a free overflow spillway. They argue that lowering the Ruth Falls Headpond is the safest and most efficient method for the project, considering environmental and safety risks.
2.2 Construction Schedule and Sequencing The Project is planned to start in May/June with the construction of the on-land portion of the downstream access path, the construction of the laydown area, and the stockpiling of clean rockfill ma...
AI summary The construction schedule for the Project begins in May/June with the on-land portion of the downstream access path, laydown area, and stockpiling of clean rockfill. Instream work and construction on the Ruth Falls Main Dam will commence only after required approvals are obtained. Following the drawdown of the Ruth Falls Headpond, temporary access paths and cofferdams will be constructed, followed by demolition work on the main dam and sluiceway.
CI 50518 CA IR-5 Attachment 7 Page 7 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Concurrently during the demolition activities, the construction work will begin with the installation of the vertical lift gates. The three-low level s...
AI summary The document outlines the construction and refurbishment activities for a sluiceway structure, including the installation of vertical lift gates, spillway overlay, and rubber dam controls. Work is scheduled to begin during demolition and continue through the summer, with an anticipated total construction period of 8-9 months, extending until March 2022.
4.2 Water Management and Control Once the desired construction elevation of 98.0 ft is reached, work will begin on the temporary upstream cofferdam/access paths. Cofferdams will be constructed to elevation 100.0 ft (30.5 m) with a crest wi...
AI summary The document discusses the construction of a temporary upstream cofferdam and access paths once a construction elevation of 98.0 ft is reached. The cofferdam will be built to an elevation of 100.0 ft with specific dimensions and materials.
CI 50518 CA IR-5 Attachment 7 Page 9 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) cofferdam/access pathwill be placed in the dry at an elevation of 98.0 ft. It is expected that elevations in Ruth Headpond will fluctuate throughout co...
AI summary The document discusses construction plans for a bypass and cofferdams at Ruth Falls Headpond to manage water levels during construction. Natural and controlled inflows from the Grant River Watershed and Malay Falls will be managed through the construction site, with oversight from NS Power engineers. A bypass will be installed to maintain water passage during Phase I.
Table 1: Estimated Discharge Flows by Bypass Reservoir Elevation (ft) Discharge (cfs) 98 620 100 1,460 Following the drawdown of Ruth Falls Headpond, the remaining section of the downstream access for the site will be completed. To cross t...
AI summary The document outlines the construction of a bypass to manage discharge flows following the drawdown of Ruth Falls Headpond. The bypass will include a 12 ft wide road, geotextile materials, and HDPE culverts. NS Power acknowledges that the bypass may not be sufficient for larger inflows, and contingency measures are discussed in Section 4.3.
Phase II of the water management strategy has been developed for periods of expected higher inflows. Once the sluiceway gates are installed and operational, water management will switch to the use of the gates as the primary method of pass...
AI summary Phase II of the water management strategy involves the use of newly installed sluiceway gates to manage higher inflows. The gates will be adjusted based on inflows and discharge requirements, and during a 1:20-year flood, the reservoir can be maintained at El. 100 ft with all three gates fully open.
Table 2: Estimated Discharge Flow from New Vertical Lift Gates(estimated based on full open position). Reservoir El. 98 ft 100 ft 102 ft 104 ft Outer Gate 1 1,544 cfs 2,874 cfs 4,453 cfs 6,246 cfs Outer Gate 2 1,544 cfs 2,874 cfs 4,453 cfs...
AI summary Table 2 presents estimated discharge flow rates from new vertical lift gates at various reservoir elevations. Appendix B includes a drawing of the proposed water control structures, and Section 4.3 discusses contingency planning related to the project.
Table 3 demonstrates the statistical flood peaks for the Ruth Falls Main Dam, from the 2008 Sheet Harbour Hydro System Flood Study.
AI summary Table 3 presents statistical flood peaks for the Ruth Falls Main Dam as outlined in the 2008 Sheet Harbour Hydro System Flood Study.
CI 50518 CA IR-5 Attachment 7 Page 11 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) sheeting and prepping the gate check to safety pass water. Since the existing structure is being modified, rather than a new structure constructed, NS...
AI summary NS Power discusses water management strategies for the Ruth Falls Headpond, including the use of existing stoplog bays, design of new vertical lift gates to withstand extreme flood events, and contingency plans for material migration and erosion risks. Regular communication with Hydro Operations is emphasized to manage high inflows and discharges effectively.
CI 50518 CA IR-5 Attachment 7 Page 12 of 103 REDACTED (CONFIDENTIAL INFORMATION REMOVED) cover any temporarily exposed work areas. Based on initial scoping of surrounding lands, NS Power has identified to potential areas to be used for wat...
AI summary NS Power is planning to use water filtration areas and sediment traps near the Ruth Falls Dam to manage sediment during construction. Silt fencing will be used on dry land, and clean rock material will be used for cofferdams to minimize sedimentation. Pumps will be used to remove silt-laden water as needed.
90% REV. 1 REVIEW SUBMITTAL NOT FOR CONSTRUCTION - I SHEET NO. QHEET I DESCRIPTION DATE REVISION STATUS NSPI DRAWING No. 100-01 DRAWING LIST ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 2020-12-18 C 90% REV. 1 REVIEW SUBMITTAL H-096H1-1631-00-0...
AI summary This document is a 90% REV. 1 review submittal for construction, containing a list of drawings and associated details such as sheet numbers, descriptions, dates, revisions, statuses, and drawing numbers related to existing and new conditions of a dam and spillway project.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam is a high priority for NS Power due to structural deterioration and stability issues. The 2021 work includes replacing deep stoplog bays with screw stem vertical lift gates and constructing a controls building and elevated concrete slab.
2.1 Existing Project Area Ruth Falls Headpond is located immediately downstream of the Malay Falls Headpond. The reservoir is contained by a 190 m (620') long earthfill embankment and a 150 m (490') long concrete spillway structure. The sp...
AI summary The Ruth Falls Headpond is located downstream of the Malay Falls Headpond and is contained by an earthfill embankment and a concrete spillway structure. The spillway includes fish migration features such as a fish ladder and a louver/fish bypass system.
Mobilization: Note: all mobilization activities will be conducted above the ordinary high water mark (OHWM) and is estimated to take two weeks. Please reference Figure 1 for a layout of site access. - A temporary access road will be constr...
AI summary Mobilization activities for the project will be conducted above the ordinary high water mark and include constructing a temporary access road, gravel crane pad, and engineered walkway to facilitate safe access to the dam and sluice bay area. Work will be carried out out of the water and is expected to take 1-2 weeks.
Sluice Gate Installation: Once the sluiceway is isolated, the new sluicegates will be installed. Below is an overview of how the new sluicegates will be installed: - The downstream stoplog checks will be prepared accordingly to accommodate...
AI summary The installation process for new sluicegates involves isolating the sluiceway, preparing downstream stoplog checks, and using a crane to install the gates. The process is expected to take approximately three months.
New Control Building (see drawing 300‐01, 02, and 05 in Appendix C): The rubber dam controls will be housed in a new control building, to be installed on the eastern end of the dam on the downstream side, see Figure 1 for location. The rub...
AI summary A new control building for rubber dam controls will be installed on the eastern end of the dam. The deck will be extended, and concrete piers will be constructed to support the building. The work is expected to take three months and will occur alongside sluice gate installation.
CI 50518 CA IR-5 Attachment 9 Page 20 of 55 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description throughout construction to ensure periods of h...
AI summary The document discusses the installation project at the Ruth Falls Dam Sluice Gate in Sheet Harbour Hydro System, emphasizing the need for erosion and sedimentation control plans during construction. NS Power is requested to provide a site-specific plan before starting activities, ensuring environmental measures are in place.
CI 50518 CA IR-5 Attachment 9 Page 31 of 55 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description APPENDIX C – ENGINEERING DRAWINGS CI 50518 CA...
AI summary The document provides information about the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project, including engineering drawings and an environmental description. The appendix contains technical drawings and is part of a regulatory proceeding in Nova Scotia.
CI 50518 CA IR-5 Attachment 10 Page 8 of 14 REDACTED (CONFIDENTIAL INFORMATION REMOVED) constructed off site and moved into place by crane. All work must be conducted in accordance with the documents submitted by the proponent in the appli...
AI summary The document outlines conditions for a watercourse alteration project, including compliance with submitted plans, obtaining necessary approvals, sediment control measures, construction timelines, and environmental mitigation strategies. It also references a Letter of Advice from DFO.
NSE Contact: Gregory Cummings APPROVAL NUMBER: 2021-2840307-00 NAME OF APPROVAL HOLDER: NOVA SCOTIA POWER INCORPORATED WORK AUTHORIZED: Dam DATE WORK WAS COMPLETED: NAME OF CONTRACTOR: COMMENTS: Signature Date CI 50518 CA IR-5 Attachment 1...
AI summary The document shows an approval for work related to a dam by Nova Scotia Power Incorporated. The approval number is 2021-2840307-00. The document is part of an attachment and includes fields for completion date, contractor name, and comments, but these are left blank.
PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2022. This work is necessary in order to address structural and freeboard deficie...
AI summary NS Power is proposing the refurbishment of the Ruth Falls Dam in Sheet Harbour, NS, to address structural issues and meet safety guidelines. The project includes replacing stop log bays with rubber dams, installing a spillway, and lowering the headpond. ECC has requested additional information on water management, contingency planning, and fish protection measures.
CI 50518 CA IR-5 Attachment 11 Page 4 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description system, e.g. as referenced in the submission,...
AI summary The document discusses the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and related environmental considerations. NS Power has provided updates on construction schedules, wetland monitoring plans, and mitigation strategies for debris and rock fill. The submission also includes information on fish ladder performance and discharge ranges during drawdown.
CI 50518 CA IR-5 Attachment 11 Page 5 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description a. Based on the information above, provide ECC...
AI summary The document discusses the Ruth Falls Dam Sluice Gate Installation Project, addressing concerns raised by ECC regarding scour observations, site access, construction plans for cofferdams, water management, ice action on temporary structures, and the elevation of the new uncontrolled spillway relative to the minimum operating level of the Ruth Falls Headpond.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam is a high priority for NS Power due to the deteriorated condition of the dam's structures. The project includes replacing stop log bays with rubber dams, installing an overflow spillway, and refacing concrete sections. A temporary drawdown of the reservoir is anticipated during construction.
CI 50518 CA IR-5 Attachment 11 Page 7 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description the primary method of isolating the existing d...
AI summary The document describes the installation of a sluice gate at the Ruth Falls Dam in Sheet Harbour Hydro System. Temporary cofferdams will be used to isolate the dam for refurbishment and manage water diversion, while the fish ladder and fish bypass will be dewatered during the process.
2.1 Existing Project Area Ruth Falls Headpond is located immediately downstream of the Malay Falls Headpond. The reservoir is contained by a 190 m (620') long earthfill embankment and a 150 m (490') long concrete spillway structure. The sp...
AI summary The Ruth Falls Headpond is part of a hydroelectric project downstream of Malay Falls. The spillway structure includes a fish ladder and louver system to aid fish migration. NS Power Hydro Operations manages water levels and flow, with specific maintenance flows to support salmon migration. There have been very few salmon captures in recent years, and the minimum operating level of the reservoir remains unchanged despite discrepancies in datums.
Phase 1 – Sluice gate installation: - Installation of a bulkhead, exact method to be determined, to isolate the existing sluiceway section. - Refurbishment of the original control building, and existing low level sluiceway section with the...
AI summary Phase 1 involves the installation of a bulkhead to isolate the existing sluiceway section, refurbishment of the control building and sluiceway, replacement of stoplogs with low-level sluice gates, and removal of the bulkhead.
Phase 2 – Dam construction: - Lowering of Ruth Falls Headpond approximately 18 ft. - Dewatering of the Ruth Falls fishladder and canal during the construction activities. - Installation of temporary access for machinery on both the upstrea...
AI summary Phase 2 of the dam construction involves lowering the Ruth Falls Headpond, dewatering the fishladder, installing temporary access roads, and modifying the spillway and dam structure, including the installation of new rubber dam bladders and a free overflow spillway section.
2.3 Construction Schedule The Project is expected to take nine months starting in April 2022 with the installation of the vertical lift gates, main dam construction in mid-July 2022, and finishing in late March 2023. This includes both the...
AI summary The Project is expected to take nine months starting in April 2022, with key milestones including the installation of vertical lift gates, main dam construction in mid-July 2022, and completion in late March 2023. The schedule includes the lowering and recharging of water in the headpond.
4.1 Water Management Once the desired construction elevation of 91.0 ft is reached, work will begin on the temporary upstream access paths. NS Power had originally requested a drawdown level of 98'; however, upon careful review of the bath...
AI summary The document discusses the decision to lower the reservoir to 91 ft for construction purposes, based on bathymetric studies showing minimal differences between 91 ft and 98 ft. This allows for a safer and more reliable construction schedule.
CI 50518 CA IR-5 Attachment 11 Page 10 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description the Ruth Falls Headpond will be lowered appro...
AI summary The Ruth Falls Dam sluice gate installation project involves lowering the headpond by 18 ft to facilitate construction. This includes dewatering the canal, fishladder, and fish bypass, while maintaining a 35 cfs flow downstream. The drawdown will be managed using the centre vertical lift gate/deep sluice bay, and flow velocities will decrease as the headpond elevation lowers over a 4-day period.
CI 50518 CA IR-5 Attachment 11 Page 12 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description water levels remain below the spillway sectio...
AI summary The document discusses the construction of the sluice gate at the Ruth Falls Dam as part of the Sheet Harbour Hydro System project. It outlines the management of water levels, temporary access roads, and contingency planning for headpond elevation fluctuations. The use of vertical lift gates is highlighted as a key measure to ensure water passage during construction.
CI 50518 CA IR-5 Attachment 11 Page 13 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description The estimated maximum discharge flows through...
AI summary This section discusses the Sheet Harbour Hydro System's Ruth Falls Dam Sluice Gate Installation Project, including an environmental description and estimated maximum discharge flows through the gates as shown in Table 2.
CI 50518 CA IR-5 Attachment 11 Page 15 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description water is expected, NS Power will notify the c...
AI summary The document outlines NS Power's contingency measures for managing water flow during the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project. It describes actions such as removing bridges, using excavators, and adjusting access roads to manage water levels during storm events and potential flood conditions.
CI 50518 CA IR-5 Attachment 11 Page 23 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description dewatered reservoir. In the event that archae...
AI summary The text discusses the installation of a sluice gate at the Ruth Falls Dam in the Sheet Harbour Hydro System. It mentions the dewatering of the reservoir and the potential for archaeological resources to be identified during the process. If such resources are found, two rounds of documentation and artifact collection will be conducted.
CI 50518 CA IR-5 Attachment 11 Page 31 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Photo 4: Downstream of Ruth Falls Dam Photo 5. Upstream of Ruth Falls Dam
AI summary The document includes redacted pages from a regulatory proceeding, with photos of Ruth Falls Dam, both downstream and upstream, indicating the focus on infrastructure and potential environmental or regulatory considerations related to the dam.
PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2022. This work is necessary in order to address structural and freeboard deficie...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam in Sheet Harbour, NS, to address structural issues and meet safety guidelines. The project involves replacing stop log bays with rubber dams and vertical lift gates, and includes dewatering activities. An addendum was submitted to the NS Department of Environment and Climate Change to address incomplete application requirements.
CI 50518 CA IR-5 Attachment 14 Page 5 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description - 6. Provide an updated 'Figure 1 – Site Plan...
AI summary The document discusses updates to the Site Plan for the Sheet Harbour Hydro System, clarifications on project components such as the bypass and modular bridge, the rationale for using 23°C as a temperature indicator, and the need for a communication plan for property owners near the headpond. These updates are in response to various queries from regulatory bodies.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam involves replacing existing stop log bays with rubber dams, installing an overflow spillway, and refacing concrete structures. The project will temporarily lower the reservoir by 18 feet and add a small permanent instream footprint for concrete work.
Phase 2 – Dam construction: - Installation of downstream access road and bridge (to start prior to drawdown activities) - Lowering of Ruth Falls Headpond approximately 18 ft. - Dewatering of the Ruth Falls fishladder and canal during the c...
AI summary Phase 2 of the dam construction involves several key activities including the installation of access roads and bridges, lowering of the headpond, dewatering of fishladder areas, and the installation of new spillway sections and walkways. These activities are part of the overall dam construction process.
2.3 Construction Schedule The construction schedule is as follows: • Phase 1, completion of new control building under approval 2021-2840307-00, will commence mid-May 2022. This work will start prior to Phase II, the lowering of Ruth Falls
AI summary The construction schedule outlines Phase 1, involving the completion of a new control building under approval 2021-2840307-00, starting mid-May 2022, before Phase II which involves lowering Ruth Falls.
CI 50518 CA IR-5 Attachment 14 Page 9 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description Headpond and Main Dam construction (see below)...
AI summary The document outlines the construction phases for the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project, including timelines for Phase II, main dam refurbishment, and sluiceway work, with completion expected by March 31st, 2023.
4.1 Water Management Once the desired construction elevation of 91.0 ft is reached, work will begin on the temporary upstream access paths. NS Power had originally requested a drawdown level of 98'; however, upon careful review of the bath...
AI summary The document discusses the water management plan for the Ruth Falls Headpond during the refurbishment of the dam. It outlines the lowering of the reservoir to 91 ft for construction, the impact on water levels, and the maintenance of a 35 cfs flow downstream. It also references the overflow spill during the switch gear refurbishment and the storage volume of the headpond.
CI 50518 CA IR-5 Attachment 14 Page 11 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description The drawdown flow will be directed through ar...
AI summary The document describes the Ruth Falls Dam Sluice Gate Installation Project, focusing on the drawdown flow process, which directs water through normal flowage channels and maintains fish passage. The headpond level is reduced from 109.25 ft to 91 ft over a 4-day period, with Table 1 showing decreased flow velocities as the elevation lowers.
CI 50518 CA IR-5 Attachment 14 Page 12 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description Once the drawdown is completed, two access ro...
AI summary The document describes the construction of access roads and a temporary bridge for the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project. It outlines the design, materials, and environmental considerations for the access roads and bridge, including storm management and contingency planning.
Table 2 : Estimated Discharge Flow for the New Vertical Lift Gates Reservoir El. 91 ft 93 ft 95 ft 97 ft 99 ft Outer Gate 1 N/A N/A 171 cfs 990 cfs 2,175 cfs Outer Gate 2 N/A N/A 171 cfs 990 cfs 2,175 cfs Middle Gate 171 cfs 990 cfs 2,175...
AI summary Table 2 provides estimated discharge flows for new vertical lift gates at different reservoir elevations. The outer gates yield identical outflows, while the middle gate has higher discharge capacities. All gates are assumed to be fully open for these calculations.
4.2 Contingency Planning The hydrological information provided in the application submission references the Sheet Harbour system flood study, which was completed as part of NS Power's dam safety program in addition to the system dam safety...
AI summary The text discusses contingency planning in the context of the Ruth Falls Dam refurbishment, referencing a flood study conducted as part of NS Power's dam safety program. The study contains confidential information and is not typically shared in watercourse alteration applications.
CI 50518 CA IR-5 Attachment 14 Page 15 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description sluiceway bays, as required for the sequencin...
AI summary The document discusses the installation of a sluice gate at the Ruth Falls Dam as part of the Sheet Harbour Hydro System project. It outlines measures to manage water levels during construction, including the use of sluice bays, monitoring of inflows, and contingency plans for unexpected high inflows or extreme weather events.
4.3 Erosion and Sedimentation Control Erosion and sedimentation control materials such as hay, silt fencing, etc., will be used to control sediment laden water from entering the headpond while it is dewatered. Any silt-laden water in the w...
AI summary The document outlines erosion and sedimentation control measures for a hydro project, including the use of silt fencing, hay, and pumps to manage sediment-laden water. It notes that past flood events have not caused erosion or scour, and that regular inspections confirm this. The project involves minimal excavation and focuses on refurbishing the existing dam structure.
CI 50518 CA IR-5 Attachment 14 Page 17 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description Figure 1: Potential locations for water filtr...
AI summary The document outlines environmental mitigation measures for the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project, including siltation monitoring, erosion and sedimentation control plans, and responses to weather events to minimize environmental impact.
CI 50518 CA IR-5 Attachment 14 Page 26 of 59 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and Environmental Description
AI summary This document discusses the Sheet Harbour Hydro System Ruth Falls Dam Sluice Gate Installation Project and includes an environmental description. A redacted image is referenced, indicating the presence of confidential or sensitive information.
PROJECT OVERVIEW NS Power is installing a new control building at the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2022. This work is necessary in order to address structural and freeboa...
AI summary NS Power is installing a new control building at the Ruth Falls Dam in 2022 as part of Phase 1 of the refurbishment project. Due to scheduling constraints, construction began in June 2022, with completion expected by the end of October 2022. NS Power is requesting a permit extension to accommodate this delay and has deferred Phase 2 to 2023 due to regulatory review delays.
Phase 1 – Control building installation: • Refurbishment of the original control building
AI summary The text outlines Phase 1 of the project, which involves the refurbishment of the original control building.
Phase 2 – Main dam construction: - Installation of downstream access road and bridge (to start prior to drawdown activities) - Lowering of Ruth Falls Headpond approximately 18 ft. - Dewatering of the Ruth Falls fishladder and canal during...
AI summary Phase 2 of the main dam construction involves several key activities, including the installation of access roads and bridges, lowering of the headpond, dewatering of fishladder and canal, and various structural modifications to the dam such as re-facing concrete and installing new spillway sections.
7. Site Specific a. This approval is for Phase 1 project components, including the installation of the control building on the Ruth Falls Dam, located on the Sheet Harbour Hydro System in Sheet Harbour, NS. The new control building will be...
AI summary The approval is for Phase 1 of a project involving the installation of a control building on the Ruth Falls Dam, part of the Sheet Harbour Hydro System in Sheet Harbour, NS, as detailed in the provided documentation.
ECC Contact: Melissa Douglas APPROVAL NUMBER: NAME OF APPROVAL HOLDER: WORK AUTHORIZED: DATE WORK WAS COMPLETED: NAME OF CONTRACTOR: Installation 2021-2840307-01 NOVA SCOTIA POWER INCORPORATED Dam September 16, 2022 Elliot Excavators Ltd....
AI summary This document contains a work approval form for the installation of a control building by Elliot Excavators Ltd. for Nova Scotia Power Incorporated, completed on September 16, 2022, with a signature date of September 20, 2022.
PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2024. This work is necessary in order to address structural and freeboard deficie...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam in Sheet Harbour, NS, in 2024 to address structural deficiencies and meet dam safety guidelines. The project includes replacing stop log bays with rubber dams, installing a spillway, and improving fish passage. Regulatory approvals have been adjusted over time, with some aspects of the project already approved and others planned for future implementation.
CI 50518 CA IR-5 Attachment 19 Page 6 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description
AI summary This document discusses the Ruth Falls Dam Refurbishment Project in Sheet Harbour, including its environmental description. Key details include the project's scope and potential environmental impacts.
2.1 Existing Project Area Ruth Falls Headpond is located immediately downstream of the Malay Falls Headpond. The reservoir is contained by a 190 m (620') long earthfill embankment and a 150 m (490') long concrete spillway structure. The sp...
AI summary The Ruth Falls Headpond is located downstream of the Malay Falls Headpond and is contained by an earthfill embankment and a concrete spillway with specific structural features. The spillway includes stop-log overflow bays, a sluiceway, and fish migration systems such as a fish ladder and louver/fish bypass.
2.2 Proposed Refurbishment Activities The proposed refurbishment activities are listed below. Please note that the installation of the control building (under separate Approval 2021-2840307-00) is complete and is not included in the scope...
AI summary The document outlines proposed refurbishment activities for a dam, including the installation of access roads, lowering of the headpond, dewatering, and improvements to fish passage and structural components. The control building installation is already complete and not part of the current scope.
2.3 Construction Schedule The construction schedule is as follows: • Installation of the downstream access roads and temporary bridge will commence in early July 2024. This work is intended to be completed prior to the drawdown in preparat...
AI summary The construction schedule outlines the installation of downstream access roads and a temporary bridge starting in early July 2024, to be completed before the drawdown of Ruth Falls Headpond in preparation for main dam construction in mid-July.
CI 50518 CA IR-5 Attachment 19 Page 10 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description - Construction activities associated with the sluiceway...
AI summary NS Power outlines the construction schedule for the Ruth Falls Dam refurbishment project, including the lowering of the headpond starting in mid-July 2024 and completion of works by April 1, 2025, with a request for an approval expiry date of December 31, 2025.
4.1 Drawdown of Ruth Heapdond In an effort to provide the safest and most reliable construction execution during one drawdown period, lowering the reservoir to elevation 91 ft is required. A construction elevation of 91 ft (approximately 1...
AI summary The document discusses the drawdown of the Ruth Heapdond reservoir to 91 ft to allow for refurbishment of the concrete dam. This involves lowering the reservoir using generating units and spillway stoplogs, with flow directed through normal channels. The process will take 8 days and includes fish rescue and dewatering of the canal and fishladder.
Table 1: Estimated Flow and Velocities for an 8-day drawdown of Ruth Falls Heapond Time (day) Beginning Elevation (ft) Bays 1-15 Bays 16-30 Outer Sluice Middle Sluice Opening (ft) Total Discharge (cfs) Velocity through each bay (fps) Downs...
AI summary The table outlines the estimated flow and velocities during an 8-day drawdown of Ruth Falls Heapond. NS Power will manage downstream flow to prevent scour and sedimentation, maintain a 35 cfs flow for fish passage, and monitor water quality and fish rescue during the process. The drawdown involves controlled sluice openings and pumping activities.
CI 50518 CA IR-5 Attachment 19 Page 13 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description Following the completion of refurbishment activities, t...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project in Sheet Harbour Hydro System, noting that following refurbishment, the headpond will be recharged at a controlled rate.
4.2 Temporary Structures Prior to the drawdown taking place, a temporary rockfill downstream access road will be constructed using clean rock that is free of fines with a crest width of 12.0 ft (3.6 m) and 1.5H:1V side slopes. The downstre...
AI summary The document describes the construction of temporary access roads and a bridge as part of a project involving a dam. These structures are made of clean rock and designed to withstand seasonal changes. The temporary bridge is removable, and the access roads are built to industry standards to allow machinery access during refurbishment activities.
CI 50518 CA IR-5 Attachment 19 Page 14 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description weather and precipitation conditions. The access roads...
AI summary The text discusses the Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project, noting that access roads pose very low risk to the project and the environment. Weather and precipitation conditions are also mentioned as relevant factors.
CI 50518 CA IR-5 Attachment 19 Page 15 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description Armour stone will be placed on the upstream side of the...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project, including measures to reinforce the downstream access road with armour stone and details about discharge flows through various structures, such as the open sluice bays, uncontrolled spillway opening, and bridge opening, as outlined in Table 2 and Section 4.4.
Table 2 : Estimated Discharge for the New Vertical Lift Gates Reservoir El. 91 ft 93 ft 95 ft 97 ft 99 ft 100 ft 101 ft 103 ft 104 ft Outer Gate 1 N/A N/A 30 cfs 180 cfs 390 cfs 510 cfs 650 cfs 940 cfs 1270 cfs Outer Gate 2 N/A N/A 30 cfs...
AI summary Table 2 presents estimated discharge rates for new vertical lift gates at various reservoir elevations. The table shows the discharge capacities for outer and middle gates, spillway, and total discharge at different elevation levels. The spillway crest is at 98ft and serves as a contingency for additional flows.
CI 50518 CA IR-5 Attachment 19 Page 16 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description and it is expected that in the event of increased water...
AI summary NS Power is refurbishing the Ruth Falls Dam, ensuring water levels can be managed during construction. They have contingency plans for extreme weather and will maintain minimum fish passage requirements, with temporary adjustments during the centre sluice bay construction.
4.4 Contingency Planning The hydrological information provided below references the Sheet Harbour system flood study, which was completed as part of NS Power's dam safety program in addition to the system dam safety reviews. NS Power does...
AI summary NS Power provides hydrological information from the Sheet Harbour system flood study as part of its dam safety program. Flood study reports are generally not included in watercourse alteration applications due to confidentiality concerns related to the dam safety program.
CI 50518 CA IR-5 Attachment 19 Page 18 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description The right downstream access road will be reinforced on...
AI summary The document details the construction and environmental considerations for the Ruth Falls Dam refurbishment project, including measures to manage water levels, infrastructure adjustments during high return period rain events, and temporary structures that can be removed to accommodate increased water flow.
CI 50518 CA IR-5 Attachment 19 Page 19 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description • Removal of any temporary formwork supporting the cons...
AI summary The document discusses the construction of the uncontrolled spillway section at the Ruth Falls Dam, including water management strategies during high return period events and the construction of upstream and downstream access roads with materials that do not impact sluiceway discharge capacity or pose significant sedimentation risks.
CI 50518 CA IR-5 Attachment 19 Page 23 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description through the fishway 35 cfs. Refer to Appendix G – Fish...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project in Sheet Harbour, including fish passage capacity at 35 cfs and references to Appendix G for fish passage assessment concept sketches.
Upstream Eel Passage An eel ramp is proposed to facilitate upstream eel passage as it was determined through the evaluation that a separate stand-alone structure was required for effective upstream eel passage, beyond the existing fishway....
AI summary An eel ramp is proposed to aid upstream eel passage, requiring a separate structure beyond the existing fishway. The design includes a metal box with climbing substrate and pumped water, placed outside the upper fishway. Hydraulic modeling confirmed the ramp's placement and entrance conditions.
CI 50518 CA IR-5 Attachment 19 Page 42 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX C – PROPOSED WATER MANAGEMENT STRUCTURES CI 50...
AI summary This document discusses the proposed water management structures for the Ruth Falls Dam Refurbishment Project in Sheet Harbour Hydro System, including an appendix and associated figures.
ISSUED FOR CONSTRUCTION REFERENCE DESCRIPTION A X,X,X,X,X X X,X,X X,X X,X,X SEAL DEPARTMENTAL APPROVALS SCALE Nova Scotia MA OFFISIO CIVI L E & I UNITS IMPERIAL POWER energy everywhere. 8 DATE Jup J MEC MEC H CONST DESIGNED ENG RUTH FALLS...
AI summary The document contains a construction-related drawing reference with technical details, including project names, dates, and approvals. It includes information about the RUTH FALLS REFURBISHMENT PROJECT and various drawing numbers and scales.
PROJECT DETAILS To accommodate refurbishments at the Ruth Falls Reservoir, the water level in the headpond will be dropped from a full supply level of 109.25 ft down to 91 ft. The headpond will remain lowered for a period of approximately...
AI summary The Ruth Falls Reservoir's water level will be lowered from 109.25 ft to 91 ft for approximately 9 months to accommodate refurbishments at the headpond.
CI 50518 CA IR-5 Attachment 19 Page 94 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations 52 0.5- 1 km. 0 53 1 - 5 km. 0 54 >5 km. 1 55 A B C D E OF11 Distance to Nearest From...
AI summary This table outlines indicators related to the distance from the center of an area (AA) to the nearest maintained public road, with specific conditions and scoring for different distance ranges. It includes instructions for measuring distances using Google Earth Pro.
CI 50518 CA IR-5 Attachment 19 Page 226 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX F – Hydraulic Modeling Report
AI summary This document is part of a regulatory proceeding related to the Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and includes an appendix with a hydraulic modeling report. The content is redacted and contains confidential information.
Table 1: Proposed Refurbishments and Changes to the Ruth Falls Dam and Explanations # Proposed Refurbishment / Change Explanation 1 Replacement of the existing stop log bay with three vertical lift gates in the center of the dam and the fl...
AI summary The document outlines proposed refurbishments to the Ruth Falls Dam, including replacing stop log bays with vertical lift gates, installing a new rubber dam, and adding fish passage weirs to improve fish passage and reduce leakage.
CI 50518 CA IR-5 Attachment 19 Page 341 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED)
AI summary The document contains redacted pages from a regulatory proceeding, including images that appear to be technical or engineering-related diagrams, likely related to Computational Fluid Dynamics (CFD) modeling or infrastructure planning.
Introduction Nova Scotia Power Inc has requested 3D hydraulic modeling to be completed at the Ruth Falls dam East River Sheet Harbour for the purpose of assessing post-refurbishment downstream river flow conditions. The main refurbishments...
AI summary Nova Scotia Power Inc requested 3D hydraulic modeling at the Ruth Falls dam to assess the impact of refurbishments on fish passage. The modeling, conducted by CBCL, evaluates changes in flow releases from new vertical lift gates and a rubber dam, focusing on fish ladder entrance conditions. Results were provided in a January 2023 memo and electronic format for further analysis.
Current flow requirements The current fishway and flows were modeled with the minimum depth over the concrete fishway notches of 1 ft, the minimum fishway flow of 6 cfs, the minimum louvre flow of 29 cfs, and the stoplog leakage and spill...
AI summary The current fishway and flows were modeled with specific minimum depth and flow parameters. Stoplog leakage increases flow in the lower fishway, but the exact amount is unknown and accounted for in gate release calculations as the new dam will not have leakage in that section.
CI 50518 CA IR-5 Attachment 19 Page 374 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 33 The fishway /louvre flow of 35 cfs is not sufficient to provide fish passage in the river below the dam. This has not been an issue due to the le...
AI summary The fishway/louvre flow of 35 cfs is insufficient for fish passage below the dam, but current leakage from stoplogs provides an additional 65 cfs. The new dam will not have this leakage, so the 65 cfs must be provided through the gates continuously.
Introduction Nova Scotia Power (NSPI) has requested an assessment of the existing downstream and upstream passage and a concept design be developed for changes needed to improve passage and to work with the proposed refurbished dam at Ruth...
AI summary Nova Scotia Power Inc. (NSPI) has requested an assessment of fish passage improvements at Ruth Falls, including a concept design for changes to the upstream and downstream passage. Detailed engineering will follow based on the concept design and regulatory review.
The lower fishway channel and entrance The current attraction to the fishway entrance is poor with the louver flow at a minimum of 29cfs coming out at right angles to the river flow and the water from the spillway aligned with the river fl...
AI summary The fishway entrance has poor attraction due to flow alignment issues, causing fish to collect away from the fishway. Additional flows from spillways contribute to turbulence and hinder fish passage. With the new dam, these flows will be relocated, potentially improving fish passage conditions.
Changes to provide improved fish passage at the refurbished dam To provide attraction flow from the fishway and eliminate the larger flow from the louvers, just downstream of the fishway entrance, the louver flow will be realigned to the t...
AI summary The document discusses changes to improve fish passage at a refurbished dam by realigning louver flow to the top of the fishway channel, as outlined in the downstream passage report.
CI 50518 CA IR-5 Attachment 19 Page 387 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) It is preferable to have the fishway entrance flow at least 10% to 15 % of the river flow, if possible, to attract the fish. The upper concrete fish...
AI summary The document discusses the importance of fishway entrance flow in attracting fish, noting that the upper concrete fishway flow provides 16% of the combined flow, and at minimum gate flow, the fishway flow can reach 39% of the total flow. During higher river flows, the fishway flow can still meet the 10% criteria.
CI 50518 CA IR-5 Attachment 19 Page 390 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the louvers will greatly improve efficiency. The passage was further hindered by stoplog overflow weirs in the outlet transition channel combined wi...
AI summary The text discusses modifications to fish passage systems, including the installation of louvers, trap funnels, and orifice openings in stop logs to improve fish movement and efficiency. These changes aim to reduce barriers and assist fish in returning upstream through the fishway.
CI 50518 CA IR-5 Attachment 19 Page 391 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX H – Louvre Assessment
AI summary This section of the document refers to the Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and includes an appendix titled 'Louvre Assessment.' The content is redacted, indicating that confidential information has been removed.
CI 50518 CA IR-5 Attachment 19 Page 394 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) canal. The fish bypass is located at the vertex of the louver V array. As previously noted, the original bypass entrance design extended the full de...
AI summary The document describes the design and modifications of a fish bypass system located at the vertex of a louver V array. The original design was modified in the late 1960s to optimize flow and increase bypass velocity. Further modifications in 2006 included closing off the lower 5 ft of the bypass entrance and constructing a new bypass channel that connects to a 32-inch diameter pipe leading to the river.
CI 50518 CA IR-5 Attachment 19 Page 400 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) passage as well as other species at a critical point where the water is accelerating and there is a change in the structure. There is also a gap whe...
AI summary The text discusses a structural gap where louvers meet the shoreline, as illustrated in Figure 7, and mentions the need to block this gap. It also refers to a point where water is accelerating and there is a change in structure, impacting other species.
5.3 The Transition from the Bypass Channel to the Pipe The next problem location is where the cement channel connects to the pipe to the river. This is a very turbulent pool as the flow drops over the stop logs down to a bottom the outlet...
AI summary The document discusses the transition from the bypass channel to the pipe, highlighting a turbulent pool where flow drops over stop logs into the outlet pipe, raising concerns about potential harm to fish and the need to reduce turbulence.
CI 50518 CA IR-5 Attachment 19 Page 403 of 423 REDACTED (CONFIDENTIAL INFORMATION REMOVED) this pool will lower the drop and a surface mounted slide gate will be installed so that the flow to the pipe can be adjusted to back up water parti...
AI summary The text discusses a proposed modification to a water flow system involving the installation of a slide gate to adjust water depth in a pool and an air vent to balance pressure in the pipe, allowing for future adjustments in louver water flow.
5.4 The louver pipe is to be realigned to enter the fishway between the upper section, the concrete fishway, and the lower section, the channel fishway that enters the river. This is to provide additional attraction flow to the fishway ent...
AI summary The louver pipe will be realigned to provide additional attraction flow to the fishway entrance, replacing the stoplog leakage that will no longer be available after the new dam is installed. The realignment includes a 3% slope and a 6.45ft drop into a 4ft deep pool, ensuring safe downstream passage according to USFW guidelines.
4.1 General A modern eel pass will be an effective option for upstream passage of eels at the re-constructed Ruth Falls dam. The location of the eel pass entrance at Ruth Falls is dependent on the flow patterns along the bottom below the r...
AI summary A modern eel pass is proposed for the re-constructed Ruth Falls dam to facilitate upstream passage of eels. The placement of the eel pass entrance depends on flow patterns below the dam under different spill flow conditions.
Municipality of the Fin Armsworthy Municipality of the Communications to advise May 2022 June 2022 NSP will update all District of Guysborough 902-533-370 District of of the Ruth Falls Head stakeholders once permits are Council Guysborough...
AI summary The text discusses communication from NSP regarding the Ruth Falls Head Pond drawdown and associated construction activities in the District of Guysborough. NSP will update stakeholders once permits are in place and has provided a project email for outreach.
REDACTED (CONFIDENTIAL INFORMATION REMOVED) CI 50518 CA IR-5 Attachment 21 Page 2 of 465 Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description
AI summary The document discusses the Ruth Falls Dam Refurbishment Project and its environmental description, including a reference to a page from a technical report or visual documentation.
Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description
AI summary The document discusses the Ruth Falls Dam Refurbishment Project in Sheet Harbour Hydro System, including its environmental description.
PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2024. This work is necessary in order to address structural and freeboard deficie...
AI summary NS Power proposes to refurbish the Ruth Falls Dam in 2024 to address structural deficiencies and meet safety guidelines. The project includes replacing stop log bays with rubber dams, installing new spillways, and improving fish passage. Regulatory approvals have been sought and revised over several years, with the latest application still under review.
2.2 Proposed Refurbishment Activities The proposed refurbishment activities are listed below. Please note that the installation of the control building (under separate Approval 2021-2840307-00) is complete and is not included in the scope...
AI summary The proposed refurbishment activities include the installation of a downstream access road and temporary bridge, as well as lowering the Ruth Falls Headpond by approximately 18 ft. The control building installation has already been completed under a separate approval.
2.3 Construction Schedule The Project is scheduled to take approximately 9 months to complete starting with the installation of the downstream access roads and temporary bridge in early July 2024. After the water is drawn down, the install...
AI summary The Project is scheduled to take approximately 9 months, starting with the installation of downstream access roads and a temporary bridge in early July 2024. The drawdown of the reservoir will occur after July 10th, taking about 8 days, with additional time incorporated to ensure controlled drawdown and minimize environmental impact.
The construction schedule is as follows: • Installation of the downstream access roads and temporary bridge will commence two weeks prior to the start of the drawdown. This work is intended to be completed prior to the drawdown in preparat...
AI summary The construction schedule outlines the installation of downstream access roads and a temporary bridge, which will begin two weeks before the drawdown starts and be completed prior to the drawdown to prepare for main dam construction in mid-July.
CI 50518 CA IR-5 Attachment 21 Page 13 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description
AI summary The document discusses the Ruth Falls Dam Refurbishment Project in Sheet Harbour Hydro System, including an environmental description and a redacted image. It appears to be part of a regulatory proceeding involving infrastructure and environmental considerations.
4.1 Drawdown of Ruth Heapdond In an effort to provide the safest and most reliable construction execution during one drawdown period, lowering the reservoir to elevation 91 ft is required. A construction elevation of 91 ft (approximately 1...
AI summary The document discusses the drawdown of Ruth Heapdond reservoir to 91 ft to allow refurbishment of the concrete dam. The process involves lowering the reservoir using generating units and spillway stoplogs, with flow directed through normal channels. The drawdown will last 8 days and will affect flow velocities.
4.2 Temporary Structures Prior to the drawdown taking place, a temporary rockfill downstream access road will be constructed using clean rock that is free of fines with a crest width of 12.0 ft (3.6 m) and 1.5H:1V side slopes. The downstre...
AI summary The document outlines the construction of temporary rockfill access roads and a temporary bridge for a project involving a dam. The temporary structures will be built using clean rock and steel beams, and will be used for machinery access during refurbishment. The access roads will be constructed upstream of the dam after a drawdown to elevation 91 ft, and will be removed once the project is completed. The structures are designed to withstand seasonal weather conditions and pose minimal environmental risk.
4.3 Water Management Planning Once the drawdown is complete, all stoplogs from the ogee spillway sections and sluiceway section will be fully removed to prepare for refurbishment activities. As shown in drawing 210-03 and 300-03 of the pro...
AI summary The document outlines the water management planning for the refurbishment of spillway sections and sluiceway at a dam. Key activities include the removal of stoplogs, demolition of concrete in bay 8, and the use of sluiceway bays to manage water levels during construction. Special considerations are made for fish passage and road reinforcement.
CI 50518 CA IR-5 Attachment 21 Page 18 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description NS Power believes that by having 9 ft of headpond capac...
AI summary NS Power is refurbishing the Ruth Falls Dam sluiceway, ensuring water level management during construction. Emergency measures, such as using the open gate bays and pumping water around the construction area, are in place to maintain minimum discharge requirements and allow fish passage. The project includes contingency planning for extreme weather events.
CI 50518 CA IR-5 Attachment 21 Page 21 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description removed. Once elevations hit 104 ft, the water would be...
AI summary The document discusses the Ruth Falls Dam Refurbishment Project, focusing on water management during construction. It outlines how the dam can handle high return period rain events, the measures to be taken during such events, and the design of access roads to avoid impacting discharge capacity.
CI 50518 CA IR-5 Attachment 21 Page 22 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description to progressively equalize around the access road. The s...
AI summary The document describes the construction approach for the access roads at the Ruth Falls Dam Refurbishment Project, including the use of large rock and riprap for reinforcement on the downstream side.
5.3 Erosion and Sedimentation Control Erosion and sedimentation control materials such as hay, silt fencing, etc., will be used to control sediment laden water from entering the headpond while it is dewatered. Any silt-laden water in the w...
AI summary NS Power outlines measures to control erosion and sedimentation during construction, including the use of silt fencing and clean rock materials. Regular monitoring and past operational success suggest no significant erosion or scour risks during high flood events. Communication with Hydro Operations and use of pumps will further mitigate sedimentation concerns.
CI 50518 CA IR-5 Attachment 21 Page 32 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description Six wetlands have been selected for monitoring. Figure...
AI summary The document discusses the selection of six wetlands for monitoring as part of the Ruth Falls Dam Refurbishment Project. These wetlands, including WL3, WL5, WL6, WL15, WL17, and WL19, are highlighted in Figure 5 and described in Table 4.
CI 50518 CA IR-5 Attachment 21 Page 33 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description Wetlands selected for monitoring were chosen based on t...
AI summary The document discusses the selection and monitoring of wetlands for the Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project. Wetlands were selected based on their diversity, geographic spread, and biodiversity. Monitoring includes vegetation, hydrology, and soil assessments. An error in GIS mapping was identified and corrected in Wetlands 5 and 16.
CI 50518 CA IR-5 Attachment 21 Page 41 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX B – SITE PHOTOS
AI summary This document provides an overview of the Ruth Falls Dam Refurbishment Project in Sheet Harbour, including site photos in Appendix B. The content is redacted due to the inclusion of confidential information.
CI 50518 CA IR-5 Attachment 21 Page 45 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX C – PROPOSED WATER MANAGEMENT STRUCTURES CI 50...
AI summary This document outlines the Ruth Falls Dam Refurbishment Project and includes Appendix C, which describes proposed water management structures. It contains visual elements such as images and figures related to the project and its environmental aspects.
CI 50518 CA IR-5 Attachment 21 Page 47 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project and Environmental Description APPENDIX D – ENGINEERING DRAWINGS CI 50518 CA IR-5 Atta...
AI summary This document contains a section of a regulatory proceeding related to the Sheet Harbour Hydro System Ruth Falls Dam Refurbishment Project, including an appendix with engineering drawings. The content is partially redacted due to confidentiality.
PROJECT DETAILS To accommodate refurbishments at the Ruth Falls Reservoir, the water level in the headpond will be dropped from a full supply level of 109.25 ft down to 91 ft. The headpond will remain lowered for a period of approximately...
AI summary The Ruth Falls Reservoir's headpond water level will be lowered from 109.25 ft to 91 ft for about 9 months to accommodate refurbishments at the reservoir.
CI 50518 CA IR-5 Attachment 21 Page 114 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E OF17 Flood Damage from Within 5 km downstream or downslope of the AA (select first true choice): Contact local authories to determine if s...
AI summary The text discusses flood risk assessment, focusing on infrastructure vulnerability to river flooding not caused by tidal storm surges. It includes criteria for evaluating flood damage and relative elevation using mapping tools such as LiDAR imagery and Google Earth's Terrain layer.
Introduction Nova Scotia Power Inc has requested 3D hydraulic modeling to be completed at the Ruth Falls dam East River Sheet Harbour for the purpose of assessing post-refurbishment downstream river flow conditions. The main refurbishments...
AI summary Nova Scotia Power Inc requested 3D hydraulic modeling for the Ruth Falls dam to assess post-refurbishment downstream river flow conditions, particularly focusing on fish passage. The modeling, conducted by CBCL, evaluates the impact of new dam structures on fish ladder entrance conditions and was used for further analysis.
Refurbished Dam Layout and Operation The plans for the dam refurbishment were used to identify where there will be fish passage issues, where changes may need to be made to the flow requirements and flow patterns to provide good fish passa...
AI summary The refurbishment plans for the dam are being analyzed to identify potential fish passage issues and determine necessary changes to flow requirements and patterns to ensure effective fish passage post-refurbishment.
Introduction Nova Scotia Power (NSPI) has requested an assessment of the existing downstream and upstream passage and a concept design be developed for changes needed to improve passage and to work with the proposed refurbished dam at Ruth...
AI summary Nova Scotia Power Inc. (NSPI) has requested an assessment of fish passage improvements at Ruth Falls, including a concept design for changes to the upstream and downstream passage. Detailed engineering will follow based on the concept design and regulatory review.
The lower fishway channel and entrance The current attraction to the fishway entrance is poor with the louver flow at a minimum of 29cfs coming out at right angles to the river flow and the water from the spillway aligned with the river fl...
AI summary The fishway entrance has poor attraction due to flow alignment issues, causing fish to collect away from the fishway. Additional flows from spillways contribute to turbulence and hinder fish passage. With the new dam, these flows will be relocated, potentially improving fish passage conditions.
Changes to provide improved fish passage at the refurbished dam To provide attraction flow from the fishway and eliminate the larger flow from the louvers, just downstream of the fishway entrance, the louver flow will be realigned to the t...
AI summary The document discusses changes to improve fish passage at a refurbished dam by realigning louver flow to the top of the fishway channel, as outlined in the downstream passage report.
CI 50518 CA IR-5 Attachment 21 Page 386 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) fishway minimum flow of 5.6cfs with a minimum louver flow of 29cfs for a total at least 34.6 as attraction flow at the fishway's river entrance. To...
AI summary The document describes the design of a fishway with specific flow requirements and structural modifications, including replacing existing weirs with new ones and providing detailed specifications for the notches and pools to ensure proper fish passage.
CI 50518 CA IR-5 Attachment 21 Page 400 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) passage as well as other species at a critical point where the water is accelerating and there is a change in the structure. There is also a gap whe...
AI summary The text discusses the structural design of a water passage, highlighting a gap between louvers and the shoreline that needs to be blocked. It references a figure illustrating the longitudinal cross section and plan view of the structure.
5.3 The Transition from the Bypass Channel to the Pipe The next problem location is where the cement channel connects to the pipe to the river. This is a very turbulent pool as the flow drops over the stop logs down to a bottom the outlet...
AI summary The document discusses the transition from the bypass channel to the pipe, highlighting a turbulent pool where flow drops over stop logs into the outlet pipe, raising concerns about potential harm to fish and the need to reduce turbulence.
CI 50518 CA IR-5 Attachment 21 Page 403 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) this pool will lower the drop and a surface mounted slide gate will be installed so that the flow to the pipe can be adjusted to back up water parti...
AI summary A slide gate will be installed to adjust water flow and partially fill a pool, dissipating energy in the flow. An air vent will be needed in the pipe to balance pressures. This adjustment allows for future changes in louver water flow.
5.4 The louver pipe is to be realigned to enter the fishway between the upper section, the concrete fishway, and the lower section, the channel fishway that enters the river. This is to provide additional attraction flow to the fishway ent...
AI summary The louver pipe will be realigned to provide additional attraction flow to the fishway entrance, replacing the stoplog leakage that will no longer be available after the new dam is installed. The realignment includes a 3% slope and a 6.45ft drop into a 4ft deep pool, ensuring safe downstream passage according to USFW guidelines.
4.1 General A modern eel pass will be an effective option for upstream passage of eels at the re-constructed Ruth Falls dam. The location of the eel pass entrance at Ruth Falls is dependent on the flow patterns along the bottom below the r...
AI summary A modern eel pass is proposed for the re-constructed Ruth Falls dam to facilitate upstream passage of eels. The placement of the eel pass entrance depends on flow patterns below the dam under different spill flow conditions.
CI 50518 CA IR-5 Attachment 21 Page 410 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 1: Bottom flow patterns (coloured by velocity) below the refurbished dam.
AI summary The document includes a figure illustrating bottom flow patterns below a refurbished dam, with velocity indicated by color. This visual representation is likely used to analyze hydrological changes or environmental impacts post-refurbishment.
CI 50518 CA IR-5 Attachment 21 Page 418 of 465 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Main Dam Refurbishment Project Application #2019-2638165-00
AI summary The document references the Ruth Falls Main Dam Refurbishment Project Application #2019-2638165-00, indicating a regulatory proceeding related to infrastructure planning and potential environmental impacts.
Overview The Sheet Harbour Hydro system, including generation at Malay Falls and Ruth Falls has been providing clean, renewable electricity to Nova Scotians for nearly one hundred years. The system requires maintenance and upgrades to ensu...
AI summary Nova Scotia Power plans to refurbish the Ruth Falls Main Dam, including replacing stoplog bays with rubber inflatable dams and sluice gates. The project requires regulatory approvals and involves lowering the headpond temporarily. A habitat offsetting project with the Mi'kmaw Conservation Group and NS Salmon Association is also part of the effort to support Atlantic Salmon recovery.
CI 50518 CA IR-5 Attachment 22 Page 10 of 11 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - q. A contingency plan shall be in place for significant rainfall events (i.e., greater than or equal to a 1 in 2-year return period storm event). -...
AI summary The text outlines requirements for contingency planning during significant rainfall events and post-excavation site restoration, including soil stabilization and re-vegetation to prevent erosion.
NON-CONFIDENTIAL $47 Managing permitting (DFO) and UARB 2024 approvals, fish passage upgrades engineering 2025 $104 Managing project execution, environmental studies, offsetting 2026 $47 Managing final months of project execution, project...
AI summary The table outlines projected costs for managing permitting, project execution, environmental studies, and offsetting activities related to fish passage upgrades and project finalization, with total estimated costs amounting to $446.
18 Description Increase in costs (in Thousands) Offsetting (West River Project) $547 Post-Construction monitoring $309 Fish passage improvements design $192 Fish count $122 Juvenile Gaspereau Entrainment Study $120 3D Hydraulic modelling $...
AI summary The text lists various cost increases related to the Ruth Falls Main Dam Refurbishment project, including fish passage improvements, monitoring plans, and design work. It references a specific regulatory proceeding (CI 50518 - HYD - NSUARB M11927) and mentions responses to information requests from The Consumer Advocate.
CI 50518 - HYD - Ruth Falls Main Dam Refurbishment ATO (NSUARB M11927) NSPI Responses to The Consumer Advocate Information Requests 1 However, NS Power does not expect this high end estimate to be required by DFO and, as 2 such, the Compan...
AI summary NS Power estimated a budget of $500,000 for offsetting the environmental impact of the Ruth Falls Main Dam Refurbishment Project, based on feedback from DFO. An additional $500,000 was included as a contingency for potential additional offsetting requirements during the regulatory review and Crown consultation process.
N-6NSPI (NSUARB) RIR-1 to 13 - Redacted
157 passages
CI 50518 - HYD - Ruth Falls Main Dam Refurbishment ATO (NSUARB M11927) NSPI Responses to NSUARB Information Requests 1 Request IR-1: 2 3 Please indicate when construction work will occur, including the estimated completion date 4 for this...
AI summary NS Power has responded to information requests regarding the Ruth Falls Main Dam Refurbishment project, indicating construction will begin in July 2025 and complete in March 2026. Approximately 10% of the project was completed by the ATO application date, and no further delays are expected, pending approval from DFO.
MEMORANDUM TO: Nova Scotia Power Inc. (NSPI) FROM: Kleinschmidt Associates Canada Inc. (Kleinschmidt) DATE: June 7, 2018 RE: RUTH FALLS REFURBISHMENT – SHEET HARBOUR HYDRO SYSTEM, SHEET HARBOUR, NS Kleinschmidt Associates Canada Inc. (Klei...
AI summary This memorandum from Kleinschmidt Associates Canada Inc. to Nova Scotia Power Inc. discusses the findings from a Dam Safety Review of the Ruth Falls Hydro System in 2015. Key deficiencies identified include insufficient freeboard, inadequate corewall elevation, slope stability issues, and concrete erosion. A site visit was conducted in 2017 to review refurbishment options.
REFURBISHMENT OPTIONS Four different refurbishment options and one new dam option were reviewed with NSPI and are described below. The feasibility of each option was evaluated by modifying the hydraulic model used for the 2015 Sheet Harbou...
AI summary The document evaluates five refurbishment options and a new dam option for Ruth Falls Dam, analyzing their feasibility using hydraulic models and stability software. Options 1 and 3 could avoid raising the dam, while Option 2 may require raising it by 1 foot. The analysis also includes an opinion of probable construction costs and conceptual sketches for visual representation.
OPTION 1: REMOVE THE STOPLOGS AND REPLACE WITH SCREW STEM VERTICAL GATES Option 1 would remove the wood stoplogs from all spillway and sluiceway bays and replace them with steel vertical slide gates. Two alternatives were considered for ga...
AI summary Option 1 proposes replacing wood stoplogs with steel vertical slide gates, allowing full control during floods. This option avoids the need to raise embankments but requires analysis of stoplog bay stability. The sluice structure is stable under all conditions. Stability factors for stoplog bays are slightly below recommended levels, necessitating potential reinforcement.
OPTION 2: REMOVE STOPLOGS TO CREATE AN UNCONTROLLED OVERFLOW SECTION WITHIN THE EXISTING SPILLWAY AND REPLACE REMAINING STOPLOGS WITH SCREW STEM VERTICAL GATES Option 2 would replace stoplog bays and piers with an uncontrolled spillway sec...
AI summary Option 2 proposes removing stoplogs to create an uncontrolled spillway section and replacing remaining stoplogs with vertical gates. The model indicates that this option would result in overtopping of the embankment by 0.75 feet when considering wave run-up and wind set-up, requiring the dam to be raised for safety. Stability analysis shows the structure meets all load cases, and the sluice structure remains stable.
OPTION 3: REMOVE THE STOPLOGS AND INSTALL A LABYRINTH SPILLWAY AND REPLACE REMAINING STOPLOGS WITH SCREW STEM VERTICAL GATES Option 3 would replace stoplog bays and piers with a labyrinth spillway section, which would pass lower frequency...
AI summary Option 3 proposes removing stoplogs and installing a labyrinth spillway with vertical slide gates. This design allows more flow at lower headpond elevations, avoids raising the embankment, and provides freeboard during peak flood conditions. Stability analysis suggests minimal modifications may be needed, and rock anchors were considered for stabilization.
OPTION 4: REMOVE THE STOPLOGS AND INSTALL AN UNCONTROLLED OVERFLOW SECTION, A RUBBER DAM, AND REPLACE SLUICEGATES WITH SCREW STEM OPERATED VERTICAL GATES Option 4 would replace fifteen stoplog bays and piers adjacent to the sluice structur...
AI summary Option 4 proposes removing stoplogs and installing an uncontrolled overflow section, a rubber dam, and replacing sluicegates with screw stem operated vertical gates. This option involves replacing fifteen stoplog bays on the river-right with an uncontrolled spillway and replacing fifteen stoplog bays on the river-left with a rubber dam. A walkway will be added, and stoplogs in the sluice structure will be replaced with vertical slide gates.
CI 50518 NSUARB IR-7 Attachment 1 Page 6 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) The length of the uncontrolled spillway section modelled was 200 feet, with a crest elevation equal to 109.2 feet, which would maintain the FSL. The...
AI summary The document discusses the design and stability considerations of a spillway section being converted from stoplog to rubber dam. It includes details on the dimensions of the spillway, hydraulic modeling results, and the need for stabilization methods such as rock anchors. The proposed design avoids the need to raise the embankment and ensures adequate freeboard during flood conditions.
OPTION 5: NEW DAM CONSTRUCTED IMMEDIATELY DOWNSTREAM OF EXISTING DAM Option 5 would utilize the existing dam spillway structure as a cofferdam to control water during construction of a new dam immediately downstream. The new dam would requ...
AI summary Option 5 proposes constructing a new dam immediately downstream of the existing dam, utilizing the existing spillway as a cofferdam. This option involves relocating part of the existing fishway and may lead to increased construction costs and environmental concerns. Two spillway designs—5A and 5B—are analyzed for the new dam.
CI 50518 NSUARB IR-7 Attachment 1 Page 7 of 34 REDACTED (CONFIDENTIAL INFORMATION REMOVED) The hydraulic model will result in similar water surface elevations during the IDF event as Options 2 through 4 listed above. With a new dam, there...
AI summary The hydraulic model indicates similar water surface elevations during the IDF event as other options. A new dam offers greater design flexibility and stability, meeting current CDA Guidelines through self-weight alone.
OPTIONS CONSIDERED BUT RULED OUT Additional options were considered during the analysis, but were ultimately ruled out for a variety of reasons. One option that was considered but ruled out was to remove every other pier from the stoplog a...
AI summary Several engineering options for gate systems were evaluated but ruled out due to technical and economic challenges. Options involving gate design, automation, and equipment selection were considered but rejected due to increased jamming risks, higher costs, and operational inefficiencies.
The OPC determined that the most cost-effective refurbishment option for the Ruth Falls spillway would be Option 4. Option 4, which involves replacing fifteen stoplog bays with an uncontrolled spillway section, and the other 15 stoplog bay...
AI summary The OPC evaluated several refurbishment options for the Ruth Falls spillway, finding Option 4 as the most cost-effective, while Option 5B was the most expensive. Differences in cost were attributed to factors like automation, materials, and structural modifications.
RECOMMENDATION Based on the results of the comparison between the three refurbishment options, Kleinschmidt recommends that Option 4 be the chosen refurbishment. Option 4 with the uncontrolled spillway section will allow for reduced operat...
AI summary Kleinschmidt recommends Option 4 for refurbishment due to its cost-effectiveness, reduced operational requirements, and automation capabilities. It includes uncontrolled spillway sections, rubber dams, and screw stem operated sluice gates, which provide better flood control and reduce the need for on-site personnel. The estimated cost is $6.61 million, potentially lower with deck-mounted operators.
ATTACHMENT 2 CONCEPTUAL SKETCHES, OPTION 4 BINDER CI 50518 NSUARB IR-7 Attachment 1 Page 15 of 34 CI 50518 NSUARB IR-7 Attachment 1 Page 16 of 34 CI 50518 NSUARB IR-7 Attachment 1 Page 17 of 34 CI 50518 NSUARB IR-7 Attachment 1 Page 18 of...
AI summary This attachment contains conceptual sketches and figures related to Option 4 from a regulatory proceeding. It includes multiple pages with visual content, likely related to infrastructure or technical planning, though no textual analysis is provided in the chunk.
(b) 7 8 (i) The percentage increase in contracts cost is 71 percent. This is primarily driven by 9 requirements associated with additional permitting requirements and increased 10 contract costs. 11 1 Totals may be off due to rounding of i...
AI summary The contract cost for the Ruth Falls Main Dam Refurbishment project has increased by 71 percent, primarily due to additional permitting requirements and increased contract costs.
REDACTED Description Increase in costs (in Thousands) ADDITIONAL SCOPE: NEW PERMITTING REQUIREMENTS Fish Passage upgrades $1,630 Engineering support for environmental permit $15 application Barn Swallow nest removal $11 Pre-tree clearing n...
AI summary The text outlines various cost increases associated with a project, including fish passage upgrades, archaeological engagement, and extended construction timelines. The table details specific line items with associated costs, such as engineering support, environmental permits, and construction-related expenses.
REDACTED 1 month and total cost included in the original NSUARB submission were 2 $133,000. However, more recent hydro projects saw site supervision costs 3 of approximately $30,000 per month. The increase in site supervision costs 4 is at...
AI summary The text discusses increased site supervision costs for a hydro project, including inflation-related increases and additional costs from project timeline changes. Freight costs for materials sourced overseas are also mentioned, which were not included in the original ACE Plan Application due to a change in manufacturing assumptions.
Examples of previous completed projects similar to this RFP: - Sissiboo Dam(1992) - Lumsden Spillway (1994) - Malay Falls Spillway (1999) - Lequille Dam & Spillway (2018) - Sandy Lake Dam & Pipeline (2012)
AI summary The text lists examples of previous completed projects similar to the RFP, including several dams and spillways constructed between 1992 and 2018.
Ruth Falls Dam Refurbishment RFP-P-20-259-01 11.3 PROJECT PLAN A. PROJECT PLAN
AI summary The document outlines the project plan for the Ruth Falls Dam Refurbishment under RFP-P-20-259-01. It includes a section labeled 'A. PROJECT PLAN' and references a picture from page 68.
11.6 QUALITY AND MONITORING All testing required for this project will be performed by Elliot Excavators Limited through an external Consultant. REDACTED CI 50518 NSUARB IR-11 Attachment 2 Page 18 of 66 Ruth Falls Dam Refurbishment RFP-P-2...
AI summary The quality and monitoring section of the document indicates that all testing for the project will be conducted by Elliot Excavators Limited through an external consultant. The document includes redacted information and references an RFP for the Ruth Falls Dam Refurbishment.
REDACTED CI 50518 NSUARB IR-11 Attachment 2 Page 52 of 66 REDACTED (CONFIDENTIAL INFORMATION REMOVED) REDACTED CI 50518 NSUARB IR-11 Attachment 2 Page 53 of 66 Ruth Falls Dam Refurbishment RFP-P-20-259-01
AI summary The document includes a redacted section from a regulatory proceeding, mentioning the 'Ruth Falls Dam Refurbishment RFP-P-20-259-01' and containing images of pages from the proceeding. The content is partially redacted, indicating confidential information has been removed.
11.13 INSURANCE/CERTIFICATIONS We have not included in our quote for Builder's Risk insurance as we will need to provide the insurance company with further information and confirmed dates. The approximate cost of this insurance will be $45...
AI summary The text discusses insurance and certification matters related to construction projects, including Builder's Risk insurance and site orientations for various infrastructure projects such as the Mersey Redevelopment Big Falls Bridge Replacement and Lake Mulgrave Dam Refurbishment.
REDACTED CI 50518 NSUARB IR-11 Attachment 2 Page 57 of 66 REDACTED (CONFIDENTIAL INFORMATION REMOVED) REDACTED CI 50518 NSUARB IR-11 Attachment 2 Page 58 of 66 Ruth Falls Dam Refurbishment RFP-P-20-259-01
AI summary The document contains a redacted page from a regulatory proceeding related to the Ruth Falls Dam Refurbishment RFP-P-20-259-01. The page includes images and is part of a larger submission, likely concerning infrastructure planning or procurement practices.
ITEM NO. DESCRIPTION UNIT APPROX. QTY UNIT PRICE TOTAL General L.S. 1 1 Mobilization L.S. 1 2 Demobilization L.S. 1 3 Environmental Management L.S. 1 4 Water Controls L.S. 1 5 Site Access L.S. 1 Demolition 1 6 General Demolition-Steel, Sto...
AI summary The document presents a detailed list of items and quantities related to a construction or infrastructure project, including mobilization, demolition, concrete work, and installation of gates and walkways. The table includes descriptions, units, and approximate quantities for various tasks, but unit prices and totals are not specified.
2.0 DESCRIPTION OF PROPOSED WORK, UNDERTAKING OR ACTIVITY NSPI is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2021. This work is necessary in order to add...
AI summary NSPI proposes to refurbish the Ruth Falls Dam to address structural and safety issues, in line with CDA guidelines. The project involves replacing stop-log bays with rubber dams and vertical lift gates, modifying spillway structures, and temporarily lowering the reservoir for construction. Fish conveyance systems will be dewatered during the work.
4.0 PHASES AND SCHEDULE The Project is expected to take six to seven months starting in May 2021 the Project and Environmental Description document submitted to NSE as part of the Watercourse Alteration Approval Application and finishing i...
AI summary The Project is expected to take six to seven months starting in May 2021, involving the lowering and recharging of water in the headpond to avoid exposing fish eggs during spawning. The detailed construction schedule will be developed by the contractor after the contract is awarded.
aged approach where two of the gates are bulkheaded for work in the dry and installed first, while maintaining the flow through the third gate. During the installation of the third gate, gates one and two will maintain the discharge of the...
AI summary The text describes a construction approach involving the installation of gates at a dam site, with two gates bulkheaded for dry work and the third maintaining fish passage during installation. Access for machinery downstream will be managed via a bypass structure, with details to be determined by the contractor.
12.0 CONTINGENCY MEASURES Both upstream and downstream fish passage will be closely monitored throughout construction. Should issues arise, the situation will be immediately assessed and decisions made regarding alternate methods by the Co...
AI summary The document outlines contingency measures for monitoring fish passage during construction. If issues arise, the Contractor, Project Manager, Engineers, Environmental Services, and Hydro Operations will assess and address them. Mitigation measures from Section 10 will be followed, and work will halt if these measures are ineffective. Environmental protocols and monitoring are emphasized to prevent significant issues.
Table 6: Residual Harm from Potential Impacts Associated with the Ruth Falls Main Dam Refurbishment Potential Effect Measure to Mitigate Serious Harm Potential Residual Serious Harm to Fish Temporary loss of fish habitat due to potential t...
AI summary The table discusses potential environmental impacts of the Ruth Falls Main Dam refurbishment, focusing on temporary fish habitat loss due to construction activities. Mitigation measures include temporary access roads, cofferdams, and fish monitoring. No residual harm to fish is anticipated.
Potential Effect Measure to Mitigate Serious Harm Potential Residual Serious Harm to Fish This can be accomplished with steel beams and building abutments out of swamp maps as an example. This will be determined by the contractor. Downstre...
AI summary The text discusses measures to mitigate serious harm to fish during a project, including the use of steel beams and building abutments based on swamp maps, and the monitoring of downstream fish passage by the contractor throughout the project duration.
CI 50518 NSUARB IR-12 Attachment 2 Page 29 of 50 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Photo 2: View of Ruth Falls Dam, facing west Photo 3: Ruth Falls fishladder and bypass pipe
AI summary The document includes photos of Ruth Falls Dam and its fishladder and bypass pipe, likely related to infrastructure and environmental considerations in a regulatory proceeding.
PROJECT OVERVIEW NSPI is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2021. This work is necessary in order to address structural and freeboard deficiencie...
AI summary NSPI is proposing to refurbish the Ruth Falls Dam in Sheet Harbour, NS, in 2021 to address structural issues and meet safety guidelines. The project includes replacing stop log bays with rubber dams, installing a spillway, and modifying the dam's structure. Fish conveyance systems will be used during construction to ensure fish movement.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam is a high priority for NS Power due to the deteriorated condition of concrete structures and stability issues in the embankment and spillway/sluiceway.
CI 50518 NSUARB IR-12 Attachment 2 Page 42 of 50 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment Application for Authorization – 34.4(2)(b) and 35(2)(b) Fisheries Act Supporting Information refurbishing the main da...
AI summary The document discusses the proposed refurbishment of the Ruth Falls Dam, including modifications to the dam structure and measures to ensure fish passage during construction. NSPI is planning to replace existing components with new structures and implement temporary measures to manage fish movement.
2.2 Proposed Refurbishment Activities The proposed maintenance activities are as follows: - installation of fish conveyance system near the entrance of the fish ladder; - lowering of Ruth Falls reservoir approximately 7‐15 feet; the actual...
AI summary The proposed refurbishment activities include the installation of a fish conveyance system near the entrance of the fish ladder and lowering the Ruth Falls reservoir by approximately 7-15 feet to ensure its proper functioning for fish passage.
CI 50518 NSUARB IR-12 Attachment 2 Page 43 of 50 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment Application for Authorization – 34.4(2)(b) and 35(2)(b) Fisheries Act Supporting Information conveyance system, passa...
AI summary This document outlines the application for authorization related to the refurbishment of the Ruth Falls Dam, including measures to ensure fish passage, dewatering of the fishladder, and construction activities such as the installation of new spillway sections and sluice gates.
CI 50518 NSUARB IR-12 Attachment 4 Page 4 of 57 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Supporting Information #1 Monitoring Activities the required 35 cfs maintenance...
AI summary The document outlines the proposed refurbishment activities at the Ruth Falls Dam, including measures to maintain water flow, installation of new sluice gates, and mitigation of environmental and safety risks. NS Power has determined that lowering the Ruth Falls Headpond is the safest and most efficient approach for the project.
PROJECT SCHEDULE The Project is planned to start in May/June with the construction of the on‐land portion of the downstream access path, the construction of the laydown area, and the stockpiling of clean rockfill
AI summary The project is planned to start in May/June with the construction of the on-land portion of the downstream access path, the construction of the laydown area, and the stockpiling of clean rockfill.
3.3 WATER MANAGEMENT AND CONTROL Once the desired construction elevation of 98.0 ft is reached, work will begin on the temporary upstream cofferdam/access paths. There will be two cofferdams installed on the upstream side of the dam placed...
AI summary The document outlines the construction of temporary upstream cofferdams and a bypass at Ruth Falls to manage water levels during the project. It details the dimensions, placement, and materials of the cofferdams, as well as measures to ensure fish passage and water control during construction.
Table 2: Estimated Discharge Flows by Bypass Reservoir Elevation (ft) Discharge (cfs) 98 620 100 1,460 Expected flows through the bypass are expected to be much lower during construction, see Section 3.4 for contingency planning for higher...
AI summary Table 2 outlines estimated discharge flows by bypass at different reservoir elevations. The document discusses construction plans for a bypass road, including specifications for its width, slope, and materials, as well as the use of HDPE culverts and contingency planning for larger inflows.
Phase II of the water management strategy has been developed for periods of expected higher inflows. Once the sluiceway gates are installed and operational, water management will switch to the use of the gates as the primary method of pass...
AI summary Phase II of the water management strategy involves using newly installed sluiceway gates to manage higher inflows. The gates will be adjusted based on inflows and discharge requirements, and under a typical 1:20-year flood scenario, the reservoir can be maintained at approximately El. 100 ft with all three gates fully open.
CI 50518 NSUARB IR-12 Attachment 4 Page 13 of 57 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Supporting Information #1 Monitoring Activities (existing stoplog bays are of...
AI summary This document outlines the monitoring activities and contingency plans for the Ruth Falls Dam Refurbishment, focusing on water management during Phase I and II, flood event handling, and material migration assessments. NS Power will ensure safety during high return period flood events and maintain communication with Hydro Operations.
90% REV. 1 REVIEW SUBMITTAL NOT FOR CONSTRUCTION 1 7 1 I REFERENCE DESCRIPTION A X, X, X, X X X, X, X X, X X, X, X SEAL DEPARTMENT AL APPROVALS S SCALE Nova Scotia 1 CIVIL POWER An Emera Company\nenergy everywhere. 1 5 MECH CONST DESIGNED...
AI summary This document is a 90% REV. 1 REVIEW SUBMITTAL for a project in Nova Scotia, including reference drawings and a drawing list. It is not for construction and appears to be part of a design or planning process.
2.0 DESCRIPTION OF PROPOSED WORK, UNDERTAKING OR ACTIVITY NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2022. This work is necessary to address...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam in 2022 to address structural deficiencies and meet dam safety guidelines. The project includes replacing stoplog bays with rubber dams and vertical lift gates, as well as constructing a free overflow spillway. Phase 1 involves the installation of sluiceway gates, which has already been approved.
Phase 2 – Dam construction: - Lowering of Ruth Falls Headpond approximately 18 feet; - Dewatering of the Ruth Falls fishladder during the construction activities; - Installation of temporary access for machinery on both the upstream and do...
AI summary Phase 2 of the dam construction involves lowering the headpond, dewatering the fishladder, and installing new spillway sections and infrastructure. Construction will begin in July 2022 and include demolition, concrete resurfacing, and installation of rubber dams. Operations will resume once the headpond returns to normal levels.
CI 50518 CA IR-5 Attachment 1 Page 6 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment Application for Authorization – 34.4(2)(b) and 35(2)(b) Fisheries Act Supporting Information The required 35 cfs maintenan...
AI summary The document outlines the application for authorization of the Ruth Falls Dam Refurbishment, addressing the provision of a 35 cfs maintenance flow and the need for a variance request for Marshall Falls operating conditions. It also describes temporary access roads and a proposed bridge design to comply with the NS Watercourse Alteration Standard.
4.0 PHASES AND SCHEDULE The Project is expected to take approximately nine months starting mid July 2022 and ending by late March 2023. The Project and Environmental Description document submitted to NSE as part of the Watercourse Alterati...
AI summary The Project is expected to take approximately nine months, starting mid-July 2022 and ending by late March 2023. It involves lowering and recharging the headpond water level, with specific timing considerations for fish migration and controlled drawdown.
Temporary loss of fish habitat (approximately 1.15 km2 ) due to lowering of the reservoir beyond the minimum operating level observed from April 1 – Nov. 30 annually. Lowering the headpond approximately 18' is required in order to complete...
AI summary The temporary loss of fish habitat due to lowering the Ruth Falls Dam reservoir is a necessary step for refurbishment. NS Power acknowledges this impact and proposes mitigation measures to reduce effects on fish habitat, including slow and controlled drawdown and maintaining water flow.
CI 50518 CA IR-5 Attachment 1 Page 32 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Photo 2: View of Ruth Falls Dam, facing west Photo 3: Ruth Falls fishladder and bypass pipe
AI summary The document includes redacted pages from a regulatory proceeding and contains images of Ruth Falls Dam and its fishladder and bypass pipe. The content is related to infrastructure and environmental considerations.
PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2022. This work is necessary in order to address structural and freeboard deficie...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam in Sheet Harbour, NS, to address structural and safety issues and comply with the Canadian Dam Association's guidelines. The project includes replacing stop log bays with rubber dams, installing a spillway, and lowering the headpond. Construction is expected to take nine months, starting in July 2022.
2.0 CONSTRUCTION Refurbishment of the Ruth Falls Dam was identified as a high priority within NS Power's dam safety risk prioritization due to the deteriorated condition of the concrete structures and the stability deficiencies in the emba...
AI summary The refurbishment of the Ruth Falls Dam is a high priority for NS Power due to deteriorated concrete structures and stability issues in the embankment and spillway. The project involves replacing stop log bays with rubber dams and installing an uncontrolled overflow spillway.
2.1 Existing Project Area Ruth Falls Headpond is located immediately downstream of the Malay Falls Headpond. The reservoir is contained by a 190 m (620') long earthfill embankment and a 150 m (490') long concrete spillway structure. The sp...
AI summary The Ruth Falls Headpond is part of a hydroelectric project with specific structural and operational features, including spillways, fish migration systems, and flow management. The document discusses the replacement of sluiceway components and the importance of maintaining minimum water levels for fish migration, particularly for Atlantic salmon.
2.2 Proposed Refurbishment Activities The proposed refurbishment activities are broken up into two phases below, Phase 1 - the installation of the sluiceway gates (already approved under Approval 2021-2840307-00) and Phase 2 – the dam cons...
AI summary The proposed refurbishment activities are divided into two phases: Phase 1 involves the installation of sluiceway gates, which has already been approved, and Phase 2 includes dam construction.
Phase 2 – Dam construction: - Lowering of Ruth Falls Headpond approximately 18 feet; - Dewatering of the Ruth Falls fishladder during the construction activities; - Installation of temporary access for machinery on both the upstream and do...
AI summary Phase 2 of the dam construction project includes lowering the Ruth Falls Headpond, dewatering the fishladder, installing temporary access roads, removing existing structures, refacing concrete, installing new spillway sections, and restoring the headpond to normal levels.
4.1 Water Management In order to expose the portions of the concrete dam to be refurbished, the Ruth Falls Headpond will be lowered approximately 18 ft from the 109.25 ft minimum operating level maintained April 1st to November 30th each y...
AI summary The Ruth Falls Headpond will be lowered by 18 ft during refurbishment, with dewatering of the canal, fishladder, and fish bypass. A 35 cfs flow will be maintained downstream. NS Power will manage the drawdown using generating units and sluice gates, ensuring minimum discharge requirements are met. The project includes constructing an access path across the spillway using clean rock.
CI 50518 CA IR-5 Attachment 1 Page 63 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment Application for Authorization – 34.4(2)(b) and 35(2)(b) Fisheries Act Supporting Information the reservoir once drawn dow...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam, which involves drawing down the reservoir, installing a temporary bridge, and managing water levels during construction. Measures include controlling downstream flow, using clean materials, and monitoring water quality and fish rescue operations.
4.2 Erosion and Sedimentation Control Erosion and sedimentation control materials such as hay, silt fencing, etc., will be used to control sediment laden water from entering the headpond while it is dewatered. Any silt-laden water in the w...
AI summary The document outlines erosion and sedimentation control measures during construction, including the use of materials like hay and silt fencing. Water quality will be monitored by NS Power, and past flood events have not caused erosion or scour. Communication between project and hydro operations personnel is emphasized to manage high inflows.
5.0 ARCHAEOLOGICAL CONSIDERATIONS An Archaeological Screening and Reconnaissance (ARIA) for the Ruth Falls Headpond was completed in 2017. The purpose of the ARIA was to assess the potential for archaeological resources in the project area...
AI summary An archaeological screening and shovel testing were conducted for the Ruth Falls Headpond project. The screening identified three areas with potential for archaeological resources, but shovel testing in two of these areas found no significant resources, allowing development to proceed.
PROJECT SCHEDULE Prior to commencing the dam construction portion of the project, the existing sluiceway structure, deep stoplog bays located in the central portion of the dam, will be replaced with screw stem vertical lift gates. No instr...
AI summary The project schedule outlines the phased construction of a dam, starting with the replacement of sluiceway structures with vertical lift gates, followed by the installation of access roads and bridge, and then the main dam construction activities including demolition, spillway overlay, and installation of rubber bladders and controls.
Table 1: Summary of potential effects on fish and/or fish habitat due to refurbishment of the Ruth Falls Dam Potential Effect Spatial Extent of Potential Effect Probability of Potential Effect Magnitude of Potential Effect Temporary loss o...
AI summary The table outlines potential environmental effects on fish and fish habitat due to the refurbishment of the Ruth Falls Dam. Effects include temporary and permanent habitat loss, fish mortality, and downstream scour, with localized spatial extents and low to medium probabilities and magnitudes.
3.5 WATER MANAGEMENT AND CONTROL Once the desired construction elevation of 91.0 ft is reached, work will begin on the temporary upstream access paths. NS Power had originally requested a drawdown level of 98'; however, upon careful review...
AI summary The document discusses the construction and water management aspects of the Ruth Falls Dam project, including the lowering of the reservoir to 91 ft for safety and reliability, spillage during the refurbishment period, and the installation of access roads and cofferdams to facilitate construction activities.
CI 50518 CA IR-5 Attachment 1 Page 77 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Monitoring Plan It is expected that elevations in the headpond will fluctuate thro...
AI summary The document outlines a monitoring plan for the Ruth Falls Dam Refurbishment, addressing water management during construction. It discusses how water will be discharged through various sluice gates, contingency planning for headpond elevation fluctuations, and the installation timeline of vertical lift gates to ensure continuous water passage.
Expected flows through the vertical lift sluice bay is expected to be much lower during construction, see Section 3.4 for contingency planning for higher inflows. Following the drawdown of headpond, the remaining section of the downstream...
AI summary The document outlines construction plans for a vertical lift sluice bay and spillway access path, including measures to manage water levels and handle storm conditions. It describes the use of clean rock material, contingency planning, and the role of NS Power in monitoring and managing water flow during construction.
Table 3: Estimated Flow Velocities Table Time (day) Beginning Elevation (ft) Middle Sluice Opening (ft) Discharge (cfs) Velocity through gate(fps) Downstream Velocity (fps) 0 109.2 1 211 21 2.4 0.5 108.8 1 209 21 2.4 1 108.0 1 204 20 2.4 1...
AI summary Table 3 presents estimated flow velocities at different times, including elevation, sluice opening, discharge, and velocities through the gate and downstream. This data may be relevant to infrastructure planning and environmental compliance.
The statistical flood peaks for the Ruth Falls headpond, taken from the 2008 Sheet Harbour Hydro System Flood Study, are presented in Table 4 below:
AI summary The document references statistical flood peaks for the Ruth Falls headpond, as outlined in the 2008 Sheet Harbour Hydro System Flood Study, presented in Table 4.
Table 4: Instantaneous Flood Peaks for the East River Return period (years) Instantaneous Flow Peaks (cfs) 2 5,850 5 8,340 10 10,130 20 11,940 50 14,430 100 16,420 1000 24,220 The instantaneous flood peaks outlined in Table 4 take into con...
AI summary Table 4 presents instantaneous flood peaks for the East River, considering inflows from the Grant River, which significantly contributes to Ruth Falls Headpond as noted in the 2008 flood study.
CI 50518 CA IR-5 Attachment 1 Page 80 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Monitoring Plan watercourse Alteration Standard (requiring a bridge to have a widt...
AI summary The document outlines NS Power's plan for managing water levels and infrastructure during the Ruth Falls Dam refurbishment, including bridge removal during high flow conditions and measures to mitigate sedimentation risks. Contingency plans are in place for significant flood events, and communication protocols are established with Hydro Operations.
CI 50518 CA IR-5 Attachment 1 Page 82 of 132 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Monitoring Plan cofferdams have been used by NS Power on other hydro refurbishment...
AI summary NS Power outlines measures to mitigate sedimentation and environmental impacts during the Ruth Falls Dam refurbishment project. These include the use of silt curtains, pumps, washed rock, and monitoring during construction. Contractors will be required to submit site-specific erosion and sedimentation control plans, and NS Power will conduct regular inspections to ensure compliance with environmental standards.
Post-Construction Monitoring NS Power will monitor the operation of the new dam structure as part of its regular bi-annual dam inspection and maintenance program as well as weekly inspections conducted by Hydro Operations. NS Power does no...
AI summary NS Power will monitor the new dam structure through regular inspections and a two-year post-construction monitoring plan. This includes an engineering assessment of the louvre system, an acoustic tracking study, and monitoring using a camera system on the fish ladder. The plan will be submitted to DFO by January 1, 2023.
PROJECT DETAILS In order to accommodate refurbishments at the Ruth Falls Reservoir, the water level in the headpond will be dropped from a full supply level of 109.25 ft down to 91 ft. The headpond will remain lowered for a period of appro...
AI summary The Ruth Falls Reservoir's water level will be lowered from 109.25 ft to 91 ft for approximately 9 months to accommodate refurbishments at the headpond.
Appendix F, Monitoring Plan Section 3.3, Pages 6-7 states, NS Power has identified areas of potential improvements to the existing louvre system that may effectively improve the efficacy of the louvre system at
AI summary Appendix F outlines a Monitoring Plan, with Section 3.3 discussing potential improvements to the existing louvre system to enhance its efficacy.
2.0 PROJECT OVERVIEW NS Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2024. This work is necessary to address structural and freeboard deficiencies...
AI summary NS Power is proposing to refurbish the Ruth Falls Dam in 2024 to address structural and safety issues, in line with the Canadian Dam Association guidelines. The project has undergone several regulatory approvals and timeline adjustments, with some components delayed or modified, including the exclusion of sluiceway refurbishment in the most recent approval.
3.1 Construction Activities The project involves the replacement of the existing 30 stoplog bays with seven (7) rubber dams, the replacement of the three (3) deep stoplog bays with vertical lift gates, the construction of a free overflow s...
AI summary The project involves replacing 30 stoplog bays with rubber dams, replacing deep stoplog bays with vertical lift gates, constructing a free overflow spillway, and refacing concrete on the dam. Upstream and downstream fish passage systems will be improved to support fish migration and eel passage.
CI 50518 NSUARB IR-12 Attachment 10 Page 10 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) The Project is scheduled to take approximately 9 months to complete starting with the installation of the downstream access roads and temporary...
AI summary The Project is scheduled to take about 9 months to complete, starting with the installation of downstream access roads and a temporary bridge in early July 2024. Construction of upstream access roads and the main dam will follow, with a new control building already constructed in 2022 to support the proposed rubber dam system.
Main Dam construction: - Installation of downstream access road and temporary bridge (to start prior to drawdown activities) Downstream access roads will need to be in place in order to access the right side of the dam - Lowering of Ruth F...
AI summary The document outlines the construction activities for the Main Dam project, including the installation of access roads, dewatering, removal of stoplogs, refacing of concrete, and installation of new spillway components. Construction is scheduled to begin in July 2024 and will include the installation of new infrastructure and the resurfacing of existing structures.
Table 1: Estimated Flow and Velocities for an 8-day drawdown of Ruth Falls Heapond Time (day) Beginning Elevation (ft) Bays 1-15 Bays 16-30 Outer Sluice Middle Sluice Opening (ft) Total Discharge (cfs) Velocity through each bay (fps) Downs...
AI summary The table outlines the estimated flow and velocities during an 8-day drawdown at Ruth Falls Heapond. NS Power will manage downstream flow to prevent environmental damage and ensure fish passage, with measures in place for water quality monitoring and fish rescue. The headpond will be recharged at a controlled rate post-refurbishment.
3.3 Temporary Structures Prior to the drawdown taking place, a temporary rockfill downstream access road will be constructed using clean rock that is free of fines with a crest width of 12.0 ft (3.6 m) and 1.5H:1V side slopes. The downstre...
AI summary The document describes the construction of temporary rockfill access roads and a temporary bridge for a project involving a dam. These structures are designed to meet industry standards and accommodate machinery during refurbishment activities. The temporary bridge is removable and designed to handle high water flow. The access roads are built with clean rock and are intended to be removed after use, with minimal environmental impact.
3.3.1 Bridge Construction and Removal Construction of the downstream bridge will take place in early July in advance of the drawdown. Construction will begin with the installation of the east downstream access road and placement of the eas...
AI summary The document outlines the construction and removal process for a downstream bridge, which will be installed in early July. The bridge will be used to facilitate the construction of access roads and the transportation of materials to the west side of the site.
CI 50518 NSUARB IR-12 Attachment 10 Page 14 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) and downstream access roads will remain in place for the duration of construction (9 months). The removal of the downstream access (roads and br...
AI summary The text describes the process for removing temporary construction structures, including roads and a bridge, over a 9-month construction period. The removal sequence and methods are outlined, emphasizing the order and steps required for dismantling the infrastructure.
3.4 Water Management Once construction begins, the sluiceway bays at the centre of the dam will be worked on first as they act as the primary means of water management, with the deepest bay in the centre of the structure constructed during...
AI summary During construction of the dam, the central sluiceway bay will be worked on first to manage water, with temporary measures in place to divert water and manage fish passage. Once completed, the central bay will be used for water management, while the outer bays and new spillway are constructed. The spillway will be available once the headpond rises to 98 ft.
Table 2 : Estimated Discharge Availability During Construction Reservoir El. 91 ft 93 ft 95 ft 97 ft 99 ft 100 ft 101 ft 103 ft 104 ft Outer Gate 1 N/A N/A 30 cfs 180 cfs 390 cfs 510 cfs 650 cfs 940 cfs 1270 cfs Outer Gate 2 N/A N/A 30 cfs...
AI summary Table 2 provides estimated discharge availability during construction at different reservoir elevations. The table includes data for outer gates, middle gate, total gate discharge, and spillway discharge. The spillway crest is at 98ft and serves as a contingency for additional flows.
3.5 Contingency Planning The hydrological information provided below references the Sheet Harbour system flood study, which was completed as part of NS Power's dam safety program in addition to the system dam safety reviews. Figure 1 below...
AI summary This section discusses contingency planning related to the Sheet Harbour system flood study, part of NS Power's dam safety program, and references the Elevation – Storage Curve for Ruth Falls from a 2008 flood study.
CI 50518 NSUARB IR-12 Attachment 10 Page 19 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Should high return period rain events (i.e. 1:10 year return period) be received during construction activities, the Ruth Falls Headpond can wit...
AI summary The document discusses flood management strategies during the construction of the Ruth Falls Headpond, including water level thresholds, infrastructure that can be removed during extreme weather events, and measures to ensure the sluiceway's discharge capacity is maintained. NS Power and the contractor will pause construction activities during high return period rain events.
CI 50518 NSUARB IR-12 Attachment 10 Page 20 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the various return period flood events down the spillway channel. High return period flood events have been safely passed as part of past normal...
AI summary The text discusses the construction and refurbishment activities at the Ruth Falls Dam, including measures to manage erosion, sedimentation, and water flow. NS Power outlines plans for excavation, water management, and environmental protection during the project.
5.0 CONSTRUCTION SCHEDULE The Project is scheduled to take approximately 9 months to complete starting with the installation of the downstream access roads and temporary bridge in early July 2024. After the water is drawn down, the install...
AI summary The construction schedule for the project outlines a 9-month timeline starting in early July 2024, including the installation of access roads, temporary bridge, and dam construction. The schedule includes careful management of water levels to protect fish, with specific phases of work planned through to April 2025.
6.0 CURRENT AND PROPOSED FACILITY OPERATION In order to achieve improved water management capabilities at the Ruth Falls dam, the proposed refurbishment will include the installation of three new vertical lift gates in place of the existin...
AI summary The proposed refurbishment of the Ruth Falls dam includes the installation of new vertical lift gates, replacement of stoplog controlled sections with rubber dam sections, and modifications to fish passage structures. These changes aim to improve water management and fish passage, resulting in altered dam operations postconstruction.
6.2 Managing Excess Water Currently, excess water is managed by pulling stoplogs either from the deep stoplog bays or overflow spillway sections of the dam. Post-construction, the majority of water control will be done using the vertical l...
AI summary Excess water management at the dam involves using stoplogs, vertical lift gates, and rubber dams. Post-refurbishment, vertical lift gates and rubber dams will be the primary methods, with the western and eastern rubber dams used in extreme conditions. The upgraded fishway can handle spill from the rubber dams. Storage capacity and headpond elevation remain unchanged.
CI 50518 NSUARB IR-12 Attachment 10 Page 31 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - The installation of a temporary bridge and access roads for machinery on both the upstream and downstream sides of the dam, resulting in a tem...
AI summary The text discusses the environmental impacts of a dam refurbishment project, including temporary habitat loss, fish passage disruptions, and mitigation measures. NS Power argues that the project will not significantly affect fish populations due to the temporary nature of the drawdown and planned improvements to fish passage infrastructure.
CI 50518 NSUARB IR-12 Attachment 10 Page 36 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 4- Site diagram outlining refurbishments associated with upstream and downstream fish passage.
AI summary This document contains a site diagram outlining refurbishments related to upstream and downstream fish passage. The figure is part of a larger regulatory proceeding and highlights infrastructure changes aimed at improving fish passage.
CI 50518 NSUARB IR-12 Attachment 10 Page 37 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Refer to Figure 5 below, Appendix H – Assessment of Upstream and Downstream Fish Passage and Appendix D - Fish Passage Engineer Designs for more...
AI summary NS Power is proposing fishway improvements at Ruth Falls, which will be monitored post-construction for two years starting in spring 2025. The improvements are designed to exceed USFWS fish passage criteria and will be implemented alongside other dam construction activities.
CI 50518 NSUARB IR-12 Attachment 10 Page 42 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) potential to create access from the west side;however, it will be accessible once the downstream access roads and bridge are installed. Temporar...
AI summary The document discusses temporary access construction for a project, noting that access will be created on the west side once downstream roads and a bridge are completed. It also outlines plans for fish monitoring and rescue during access road installation and describes a drawdown schedule for Ruth Headpond to minimize fish entrainment and mortality.
Table 8 - Residual Harm from Potential Impacts Associated with the Ruth Falls Dam Refurbishment Potential Effect Measure to Mitigate Serious Harm Potential Residual Serious Harm to Fish Loss of ~60 m2 of fish habitat in the East River of S...
AI summary Table 8 outlines the residual harm from potential impacts associated with the Ruth Falls Dam Refurbishment, specifically addressing the loss of fish habitat in the East River of Sheet Harbour and the mitigation measures taken to avoid residual harm to fish.
CI 50518 NSUARB IR-12 Attachment 10 Page 59 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) APPENDIX C – ENGINEERING DRAWINGS – DAM STRUCTURE
AI summary This section of the document contains Appendix C, which includes engineering drawings related to a dam structure. The content is redacted and confidential, and it includes several images of technical drawings.
2.0 LOUVRE SYSTEM The louvre system at the Ruth Falls Dam was originally installed in 1966 as a downstream bypass and counting facility for the passage of Atlantic salmon smolts. The louvre system is a series of vertical slats arranged in...
AI summary The Louvre system at the Ruth Falls Dam, installed in 1966, serves as a downstream bypass and counting facility for Atlantic salmon smolts. It consists of vertical slats arranged in a V pattern, with modifications made over time, including a change from a bottom to a top outlet pipe to better accommodate salmon smolts and other pelagic species.
CI 50518 NSUARB IR-12 Attachment 10 Page 108 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) APPENDIX G – HYDRAULIC MODELING RESULTS
AI summary This section presents hydraulic modeling results as part of the regulatory proceeding, likely related to infrastructure planning or grid modernization efforts in Nova Scotia.
Background This report addresses the request made by Nova Scotia Power (NSP) by email on the 8 th February, 2022, and following discussions. An excerpt is presented below to present the requested scope of work: We have determined a need fo...
AI summary Nova Scotia Power (NSP) requested 3D hydraulic modeling for the Ruth Falls dam to assess post-refurbishment downstream conditions, focusing on the impact of new vertical lift gates and a rubber dam on fish ladder entrance conditions. The request includes considerations of historic and proposed gate operations, flow measurements, maintenance schedules, and site geometry.
CI 50518 NSUARB IR-12 Attachment 10 Page 116 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) - S2: 6 cfs from the fishway, 29 cfs from the louvres outfall, 165 cfs from the gates - S3: 6 cfs from the fishway, 29 cfs from the louvres out...
AI summary The text provides flow values (in cubic feet per second) for different scenarios (S2 to S7) related to fishway, louvres outfall, and gates. It also references figures illustrating existing and redesigned weir and louvres outflow configurations, including variations with and without rock diversion.
4. Model Results of Scenario S4 with 1720 cfs from the gates Figure S4-1: Plan view of the Water Surface Velocities Figure S4-2: Plan view of the Mid-Surface Velocities Figure S4-3: View of the Bottom Velocities Figure S4-4: Zoom-in view o...
AI summary This section presents model results for Scenario S4 with a flow rate of 1720 cfs from the gates, including multiple figures showing velocity vectors at different locations such as the fishway, downstream of the gates, and the middle and end of the channel.
Table 1: Proposed Refurbishments and Changes to the Ruth Falls Dam and Explanations # Proposed Refurbishment / Change Explanation 1 Replacement of the existing stop log bay with three vertical lift gates in the center of the dam and the fl...
AI summary The document outlines proposed refurbishments to the Ruth Falls Dam, including the replacement of stop logs with vertical lift gates, installation of a new rubber dam, and the addition of fish passage weirs to improve fish passage and structural integrity.
Refurbished Dam Layout and Operation The plans for the dam refurbishment were used to identify where there will be fish passage issues, where changes may need to be made to the flow requirements and flow patterns to provide good fish passa...
AI summary The refurbishment plans for the dam are being analyzed to identify potential fish passage issues and determine necessary changes to flow requirements and patterns to ensure effective fish passage post-refurbishment.
CI 50518 NSUARB IR-12 Attachment 10 Page 256 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 33 The fishway /louvre flow of 35 cfs is not sufficient to provide fish passage in the river below the dam. This has not been an issue due to t...
AI summary The fishway/louvre flow of 35 cfs is insufficient for fish passage below the dam, but current leakage from stoplogs provides additional flow. The new dam will not have this leakage, so 65 cfs should be provided through the gates continuously.
Changes to provide improved fish passage at the refurbished dam To provide attraction flow from the fishway and eliminate the larger flow from the louvers, just downstream of the fishway entrance, the louver flow will be realigned to the t...
AI summary The document discusses changes to improve fish passage at a refurbished dam by realigning louver flow to the top of the fishway channel, as outlined in the downstream passage report.
4. Description of the Louvers As shown in Figures 2 and 3, the louvers are arranged in a V pattern across the intake canal and consist of steel bars orientated perpendicular to the flow. Each leg of the V is approximately 50 ft long and or...
AI summary The louvers are arranged in a V pattern across the intake canal, made of steel bars oriented perpendicular to the flow. Each leg of the V is about 50 ft long, angled 12 degrees to the approach flow, with a fish bypass located downstream at the vertex.
CI 50518 NSUARB IR-12 Attachment 10 Page 282 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) passage as well as other species at a critical point where the water is accelerating and there is a change in the structure. There is also a ga...
AI summary The passage discusses structural gaps where louvers meet the shoreline, as illustrated in Figure 7, and highlights the need to block these gaps to address issues related to water acceleration and structural changes.
5.2 Keep the Fish in the Bypass Channel and Improve Downstream Passage In the concrete channel, it is proposed that a trap funnel be installed at the most upstream stop log guide. This funnel would narrow the opening to 1.25ft and lead the...
AI summary The proposal includes installing a trap funnel at the upstream stop log guide in the concrete channel to prevent fish from returning upstream and modifying the 6 stop log sections to include bottom orifices for improved downstream passage for all species.
CI 50518 NSUARB IR-12 Attachment 10 Page 285 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) this pool will lower the drop and a surface mounted slide gate will be installed so that the flow to the pipe can be adjusted to back up water...
AI summary A slide gate will be installed to adjust water flow and manage water depth in a pool, partially filling it to dissipate energy. An air vent will also be needed to balance pressures in the pipe. Adjustments will accommodate future changes in louver water flow.
1.0 Introduction This monitoring plan outlines NS Power's proposed monitoring activities, and additional avoidance and mitigation measures for the Ruth Falls Dam Refurbishment Project (the Project) as well addresses DFO's request for addit...
AI summary NS Power's monitoring plan for the Ruth Falls Dam Refurbishment Project outlines proposed activities, including entrainment and wetland monitoring, as well as construction activities such as lowering the headpond and installing new spillway sections. The plan also addresses DFO's request for additional information.
1.1 PROJECT SCHEDULE The Project is scheduled to take approximately 9 months to complete starting with the installation of the downstream access roads and temporary bridge starting in late June 2024 (refer to the project schedule Gantt cha...
AI summary The project is scheduled to take about 9 months, starting with the installation of downstream access roads and a temporary bridge in late June 2024. Main dam construction will begin in mid-July 2024 after the drawdown of the Ruth Falls Headpond, which will occur over 8 days starting no earlier than July 10th to minimize environmental impact.
Ruth Falls Dam Rebuild Fish Entrainment Monitoring Program - Field Plan January 31, 2023 Prepared for: Nova Scotia Power Incorporated Prepared by: Stantec Consulting Ltd. 102-40 Highfield Park Drive Dartmouth NS B3A 0A3
AI summary This document outlines the Fish Entrainment Monitoring Program field plan for the Ruth Falls Dam Rebuild project, prepared by Stantec Consulting Ltd. for Nova Scotia Power Incorporated.
PROJECT DETAILS To accommodate refurbishments at the Ruth Falls Reservoir, the water level in the headpond will be dropped from a full supply level of 109.25 ft down to 91 ft. The headpond will remain lowered for a period of approximately...
AI summary The Ruth Falls Reservoir's water level will be lowered from 109.25 ft to 91 ft for approximately 9 months to accommodate refurbishments at the reservoir.
CI 50518 NSUARB IR-12 Attachment 10 Page 586 of 591 REDACTED (CONFIDENTIAL INFORMATION REMOVED) No changes have been made to the fish ladder and louver system since 2010, therefore NSPI proposesto conduct the assessment studies following t...
AI summary NSPI proposes to conduct fish passage efficiency studies after completing modifications to the fish ladder and louver system at Ruth Falls. Construction is expected to start in July 2024, with post-construction assessments planned to evaluate the improvements.
2.0 PROJECT OVERVIEW Nova Scotia (NS) Power is proposing refurbishment of the Ruth Falls Dam (the "Project"), located on the Sheet Harbour Hydro System in Sheet Harbour NS, in 2024. This work is necessary to address structural and freeboar...
AI summary Nova Scotia Power is proposing to refurbish the Ruth Falls Dam in 2024 to address structural and safety issues. The project is necessary to comply with dam safety guidelines and has undergone several regulatory approvals and adjustments since 2019. The scope has changed over time, with some components, like the sluiceway refurbishment, being excluded in later approvals.
3.1 Construction Activities The project involves the replacement of the existing 30 stoplog bays with seven (7) rubber dams, the replacement of the three (3) deep stoplog bays with vertical lift gates, the construction of a free overflow s...
AI summary The project entails replacing 30 stoplog bays with seven rubber dams, replacing three deep stoplog bays with vertical lift gates, constructing a free overflow spillway, and refacing concrete on the main dam. Fishway and louvre system improvements are also planned to enhance fish passage.
CI 50518 NSUIARB IR-12 Attachment 12 Page 5 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) migrating around the dam to complete their lifecycle. The addition of an upstream eel pass will also be installed to support specific upstream p...
AI summary The project involves modifying the Ruth Falls dam to improve fish passage and install a new rubber dam system. Construction will begin in July 2024 and include the installation of upstream and downstream access roads, dewatering, and the construction of a new control building. The project will not alter discharge flows after completion.
CI 50518 NSUIARB IR-12 Attachment 12 Page 6 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) resurfaced, the rubber dams will be installed and connected to the controls building which will has already been installed under Approval 2021-2...
AI summary NS Power plans to install rubber dams and replace concrete structures as part of a construction project. The project includes modifications to improve fishway efficiency and will involve submission of materials for approval based on health, safety, and environmental criteria.
3.2 Drawdown The reservoir will be temporarily drawn down approximately 18 ft, which serves as the primary method of isolating the existing dam structure for refurbishment activities. During the time the water is drawn down, NS Power inten...
AI summary The reservoir will be temporarily drawn down by approximately 18 ft to allow for refurbishment of the dam structure. NS Power will ensure fish passage during construction, except when the center sluice gate is under construction. The drawdown to 91 ft is necessary for full exposure of the dam for refurbishment and will be managed through the removal of spillway and sluiceway stoplogs.
CI 50518 NSUIARB IR-12 Attachment 12 Page 8 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) water using the drain valve at the powerhouse. Following the completion of refurbishment activities, the headpond will be subsequently recharged...
AI summary The text discusses the refurbishment activities at Ruth Falls, including controlled recharging of the headpond and spill management practices. It notes that spill discharges during normal operations range from 175 to 990 cfs and that drawdown discharges would not exceed these levels.
3.3 Temporary Structures Prior to the drawdown taking place, a temporary rockfill downstream access road will be constructed using clean rock that is free of fines with a crest width of 12.0 ft (3.6 m) and 1.5H:1V side slopes. The downstre...
AI summary The document outlines the construction of temporary rockfill access roads and a temporary bridge for a dam project. These structures will be built using clean rock, with specific dimensions and slopes, and will be used for machinery access during refurbishment. The temporary bridge is designed to be removable and will be used during construction. No cofferdams are required for the project, and the access roads are designed to withstand all weather conditions.
CI 50518 NSUIARB IR-12 Attachment 12 Page 9 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the water will flow downstream through the sluiceway bay and under the temporary bridge, see Appendix E- Proposed Water Management Structures fo...
AI summary The text describes the flow of water downstream through the sluiceway bay and under a temporary bridge, with additional details provided in Appendix E regarding proposed water management structures.
3.3.1 Bridge Construction and Removal Construction of the downstream bridge will take place in early July in advance of the drawdown. Construction will begin with the installation of the east downstream access road and placement of the eas...
AI summary The construction of a downstream bridge and access roads will begin in early July, with the bridge used to transport materials for building the west access road. The structures will remain in place for nine months and will be removed in the reverse order of installation, with the bridge being dismantled last.
3.4 Water Management Once construction begins, the sluiceway bays at the centre of the dam will be worked on first as they act as the primary means of water management. The deepest bay in the centre of the structure construction is planned...
AI summary The sluiceway bays at the dam will be constructed in stages, with the central bay being worked on first during low flow periods. A steel barrier and pumps will be used to manage water during construction. Once complete, the central bay will be used for water management, and the new uncontrolled spillway in bay 8 will be constructed later to handle higher water levels.
CI 50518 NSUIARB IR-12 Attachment 12 Page 14 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Should high return period rain events (i.e. 1:10 year return period) occur during construction activities, the Ruth Falls Headpond can withstan...
AI summary The document outlines water management strategies during the construction of the Ruth Falls Headpond, including measures to handle high return period rain events, temporary infrastructure removal, and the construction of access roads that do not interfere with sluiceway discharge capacity.
CI 50518 NSUIARB IR-12 Attachment 12 Page 15 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the various return period flood events down the spillway channel. High return period flood events have been safely passed as part of past norma...
AI summary The document discusses flood management and erosion control measures for the Ruth Falls Dam project. It outlines inspection protocols, sedimentation control strategies, and water management plans to ensure environmental protection during construction. NS Power will use rockfill cofferdams, silt fencing, and designated filtration areas to minimize environmental impact.
5.0 CONSTRUCTION SCHEDULE The Project is scheduled to take approximately nine (9) months to complete starting with the installation of the downstream access roads and temporary bridge in early July 2024. After the water is drawn down, the...
AI summary The construction schedule for the Project outlines a nine-month timeline starting in early July 2024, including the installation of access roads, temporary bridges, and dam construction. The schedule includes a controlled drawdown of the Ruth Falls Headpond to minimize environmental impact and ensure fish migration. Key activities include sluice gate installation, dam refurbishment, fish passage improvements, and final commissioning by April 2025.
6.0 CURRENT AND PROPOSED FACILITY OPERATION In order to achieve improved water management capabilities at the Ruth Falls dam, the proposed refurbishment will include the installation of three new vertical lift gates in place of the existin...
AI summary The proposed refurbishment of the Ruth Falls dam includes new vertical lift gates, rubber dam sections, and adjustments to fish passage structures. These changes will improve water management and fish migration, resulting in altered dam operations post-construction.
6.2 Managing Excess Water Currently, excess water is managed by pulling stoplogs either from the deep stoplog bays or overflow spillway sections of the dam. Post-construction, the majority of water control will be done using the vertical l...
AI summary Excess water management at the dam involves using stoplogs, vertical lift gates, and rubber dams. Post-refurbishment, vertical lift gates and rubber dams will be the primary means of managing water, with the western and eastern rubber dams used in extreme conditions. The fishway is designed to handle spill from the eastern rubber dam if necessary.
CI 50518 NSUIARB IR-12 Attachment 12 Page 35 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 6- Cross-section view of proposed slanted ramp Detailed designs of the louvre system improvements can be found in Appendix D. These impr...
AI summary The document discusses proposed improvements to the louvre system, which will be implemented alongside other dam construction activities. NS Power is committed to conducting an eel pit-tagging study to assess the impact of these changes on eel migration, with details provided in appendices.
CI 50518 NSUIARB IR-12 Attachment 12 Page 38 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) temporary access roads sit within the drawdown area. On the upstream side, access roads will be placed after the headpond has been drawn down a...
AI summary The text discusses the construction of temporary access roads within a drawdown area, including fish monitoring and rescue during installation. It also outlines challenges in maintaining a 35 cfs maintenance flow during construction, particularly when the centre bay is being worked on, and the use of pumping to maintain downstream fish passage.
controlled to rubber dam spillway the fishway entrance. This includes designing for appropriate velocities to allow for prolongedswimming and burst swimming for species looking to migrate upstream. With respect to loss of some surface down...
AI summary NS Power is addressing fish passage improvements at the Ruth Falls fishway by installing vertical lift gates and rubber dams. Surface downstream passage will still be available through the rubber dams and free overflow sections. NS Power will conduct post-construction monitoring to assess the effectiveness of the improvements and has committed to a pit tagging study to evaluate the efficiency of the louvre system.
Table 10 - Residual Harm from Potential Impacts Associated with the Ruth Falls Dam Refurbishment Potential Effect Measure to Mitigate Serious Harm Potential Residual Serious Harm to Fish enough water is available to maintain a 35 cfs flow...
AI summary Table 10 outlines residual harm from potential impacts associated with the Ruth Falls Dam Refurbishment, focusing on water flow below the dam and mitigation measures to prevent serious harm to fish.
CI 50518 NSUIARB IR-12 Attachment 12 Page 55 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Photo 4: Downstream of Ruth Falls Dam Photo 5. Upstream of Ruth Falls Dam
AI summary The document contains two photos related to Ruth Falls Dam, one showing the downstream area and the other showing the upstream area. The context suggests these images may be part of a regulatory proceeding related to infrastructure or environmental considerations.
REFERENCE DESCRIPTION A ×, ×, ×, ×, × ×, ×, ×, ×, ×, ×, ×, × SEAL DEPARTMENTAL APPROVALS SCALE Nova Scotia 200-03 210-01 EXISTING CONDITIONS WEST SPILLWAY DAM PLAN AND SECTIONS TEMPORARY CONDITIONS/DEMO PLAN 2020-12-11 C 90% REV. 1 REVIEW...
AI summary The document references a spillway dam plan and temporary conditions/demo plan for the West Spillway Dam, with submission details and approval status as of December 11, 2020.
2.0 LOUVRE SYSTEM The louvre system at the Ruth Falls Dam was originally installed in 1966 as a downstream bypass and counting facility for the passage of Atlantic salmon smolts. The louvre system is a series of vertical slats arrangedina...
AI summary The Louvre system at the Ruth Falls Dam, installed in 1966, is a downstream bypass and counting facility for Atlantic salmon smolts. It consists of vertical slats arranged in a V pattern across the intake canal, with modifications made over the years, including a switch from a bottom to a top outlet pipe to better accommodate fish passage.
3.2 American eel study A fall (2009) study of the bypass was also undertaken to assess passage of downstream migrating silver eels. Between September 28 and November 12 NSP monitored the fish bypass. More than 3300 fish were documented and...
AI summary A 2009 study by NSP monitored fish passage through a bypass facility, documenting over 3300 fish, primarily alewife and American eels. Of the 1082 eels identified, 165 were silver eels. NSP tagged 148 eels, with 40 detected downstream, suggesting a 30% bypass efficiency. The study also noted the presence of other fish species, but their numbers were low.
CI 50518 NSUIARB IR-12 Attachment 12 Page 110 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) APPENDIX G – HYDRAULIC MODELING RESULTS
AI summary This section presents hydraulic modeling results, which are likely related to infrastructure planning or grid modernization efforts within the Nova Scotia regulatory proceeding.
CI 50518 NSUIARB IR-12 Attachment 12 Page 258 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 33 The fishway /louvre flow of 35 cfs is not sufficient to provide fish passage in the river below the dam. This has not been an issue due to...
AI summary The fishway/louvre flow of 35 cfs is insufficient for fish passage below the dam. Current leakage from stoplogs compensates for this, but the new dam will not have this leakage, requiring the 65 cfs to be provided through the gates continuously.
Pool and Wier fishway design background Pool-and-weir fishways are very sensitive to water level fluctuations at both the upstream and downstream ends. In these fishways, low tailwater levels will result in a high drop out the entrance not...
AI summary Pool-and-weir fishways are highly sensitive to water level fluctuations, which can affect fish passage by altering velocities, turbulence, and water depths. Both low and high water levels can create conditions that hinder fish movement through the fishway.
Changes to provide improved fish passage at the refurbished dam To provide attraction flow from the fishway and eliminate the larger flow from the louvers, just downstream of the fishway entrance, the louver flow will be realigned to the t...
AI summary The document discusses changes to improve fish passage at a refurbished dam by realigning louver flow to the top of the fishway channel, as outlined in the downstream passage report.
CI 50518 NSUIARB IR-12 Attachment 12 Page 270 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) fishway minimum flow of 5.6cfs with a minimum louver flow of 29cfs for a total at least 34.6 as attraction flow at the fishway's river entranc...
AI summary The document outlines the design modifications to a fishway to ensure adequate flow for fish passage. It specifies the replacement of existing weirs with 11 new weirs, details the dimensions and slope of notches, and mentions the inclusion of resting areas in pools to facilitate fish movement.
CI 50518 NSUIARB IR-12 Attachment 12 Page 274 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) the louvers will greatly improve efficiency. The passage was further hindered by stoplog overflow weirs in the outlet transition channel combi...
AI summary The document describes modifications to a fish passage system, including the installation of trap funnels and orifice openings in stop logs to improve fish movement and efficiency. These changes aim to reduce barriers and assist fish in returning to the power canal.
4. Description of the Louvers As shown in Figures 2 and 3, the louvers are arranged in a V pattern across the intake canal and consist of steel bars orientated perpendicular to the flow. Each leg of the V is approximately 50 ft long and or...
AI summary The louvers are arranged in a V pattern across the intake canal, composed of steel bars oriented perpendicular to the flow. Each leg of the V is approximately 50 ft long and oriented 12 degrees to the approach flow, with a fish bypass located downstream at the vertex.
CI 50518 NSUIARB IR-12 Attachment 12 Page 278 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) canal. The fish bypass is located at the vertex of the louver V array. As previously noted, the original bypass entrance design extended the f...
AI summary The text describes the design and modifications of a fish bypass located at the vertex of a louver V array in a canal. It details the original and 2006 modified designs, including dimensions, materials, and flow characteristics, as well as the location of the bypass relative to other structures.
CI 50518 NSUIARB IR-12 Attachment 12 Page 284 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) passage as well as other species at a critical point where the water is accelerating and there is a change in the structure. There is also a g...
AI summary The passage discusses structural issues in a water-related facility, including gaps between louvers and the shoreline that need to be addressed. It references a figure showing a longitudinal cross section and plan view of the structure.
5.3 The Transition from the Bypass Channel to the Pipe The next problem location is where the cement channel connects to the pipe to the river. This is a very turbulent pool as the flow drops over the stop logs down to a bottom the outlet...
AI summary The transition from the bypass channel to the pipe is identified as a problematic location due to turbulence caused by the flow dropping over stop logs into the outlet pipe, potentially harming fish. The orifice in the stoplog section entrance is mentioned as a point of concern.
CI 50518 NSUIARB IR-12 Attachment 12 Page 287 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) this pool will lower the drop and a surface mounted slide gate will be installed so that the flow to the pipe can be adjusted to back up water...
AI summary A slide gate will be installed to adjust water flow into a pool, allowing for partial filling and energy dissipation. The pipe will also require an air vent to balance pressures.
5.4 The louver pipe is to be realigned to enter the fishway between the upper section, the concrete fishway, and the lower section, the channel fishway that enters the river. This is to provide additional attraction flow to the fishway ent...
AI summary The louver pipe will be realigned to provide additional attraction flow to the fishway entrance, replacing stoplog leakage. The new design ensures safe downstream passage in accordance with USFW guidelines.
CI 50518 NSUIARB IR-12 Attachment 12 Page 294 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 1: Bottom flow patterns (coloured by velocity) below the refurbished dam.
AI summary This page from a regulatory proceeding document includes a figure depicting bottom flow patterns below a refurbished dam, coloured by velocity. The figure is part of a larger document that contains confidential information.
CI 50518 NSUIARB IR-12 Attachment 12 Page 304 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Ruth Falls Dam Refurbishment S 35(2)(b) Fisheries Act Authorization Monitoring Plan NS Power has considered the potential environmental and ar...
AI summary NS Power has evaluated the environmental and safety risks of lowering the Ruth Falls Headpond for the refurbishment project and determined it to be the safest and most efficient approach, despite considering alternatives like bulkheads and cofferdams which present significant risks.
1.1 PROJECT SCHEDULE The Project is scheduled to take approximately nine (9) months to complete starting with the installation of the nine (downstream access roads and temporary bridge starting in late June 2024 (refer to the project sched...
AI summary The project is scheduled to take nine months, starting with the installation of downstream access roads and a temporary bridge in late June 2024. Main dam construction will begin in mid-July after the drawdown of Ruth Falls Headpond, with measures in place to minimize environmental impact.
PROJECT DETAILS To accommodate refurbishments at the Ruth Falls Reservoir, the water level in the headpond will be dropped from a full supply level of 109.25 ft down to 91 ft. The headpond will remain lowered for a period of approximately...
AI summary The Ruth Falls Reservoir's water level will be lowered from 109.25 ft to 91 ft for approximately 9 months to accommodate refurbishments at the reservoir.
CI 50518 NSUIARB IR-12 Attachment 12 Page 372 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations OF17 Flood Damage from Non Within 5 km downstream or downslope of the AA (selec...
AI summary The table outlines indicators for assessing flood damage from non-tidal waters, focusing on the presence of infrastructure vulnerable to river flooding. It provides conditions for evaluating flood risk based on mapping data and local infrastructure.
CI 50518 NSUIARB IR-12 Attachment 12 Page 380 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 293 >95% of the AA. 0 F62 BMP - Soils Boardwalks, paved trails, fences or other infrastructure and/or well-enforced regulations appe...
AI summary This table outlines various Best Management Practices (BMPs) and consumptive uses within an Area of Assessment (AA). It includes infrastructure measures to protect soil and wildlife, as well as potential sustainable consumptive activities such as hunting, fishing, and trapping.
CI 50518 NSUIARB IR-12 Attachment 12 Page 412 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 2 93 surges. Maps show Flood Zone or Flood Risk areas, but infrastructure is absent or is not vulnerable to floods from a non-tidal river. In...
AI summary The text discusses flood risk mapping and infrastructure vulnerability, noting that some areas have flood zones or risk areas, but infrastructure may not be vulnerable due to protective measures. In contrast, other areas lack flood mapping and have infrastructure at risk from river flooding unrelated to tidal surges.
CI 50518 NSUIARB IR-12 Attachment 12 Page 432 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) 3 # Indicators Condition Choices Data Definitions/Explanations 92 tidal Waters Maps show Flood Zone or Flood Risk areas and there appears to b...
AI summary The text discusses flood risk indicators, including tidal waters, flood zones, and infrastructure vulnerability. It provides conditions for evaluating flood risk based on mapping data and elevation, with specific references to tools like Google Earth and the NS_Watersheds Secondary KMZ file.
CI 50518 NSUIARB IR-12 Attachment 12 Page 460 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) A B C D E 114 F21 Invasive Cover Along Upland Edge Along the wetland-upland boundary, the percent of the upland edge (within 3 m upslope from...
AI summary The text outlines assessment criteria for wetland features, including invasive plant cover along upland edges and characteristics of fringe and lacustrine wetlands. It provides definitions and instructions for evaluating these features, with specific categories and codes for data entry.
CI 50518 NSUIARB IR-12 Attachment 12 Page 572 of 576 REDACTED (CONFIDENTIAL INFORMATION REMOVED) Figure 1 Proposed hydrophone deployment locations in headpond and intake canal entrance upstream of louvres
AI summary The text references a figure titled 'Proposed hydrophone deployment locations in headpond and intake canal entrance upstream of louvres,' indicating a discussion related to infrastructure planning and environmental monitoring in a hydroelectric context.
Ruth Falls Dam Refurbishment project (phase 2): - Concern with the removal of approximately 6.35 million m3 of water over 9 months: - Significant exposure time and removal of habitat is sure to permanently destroy more of the habitat than...
AI summary The Ruth Falls Dam Refurbishment project (phase 2) raises concerns about the environmental impact of removing 6.35 million m3 of water over 9 months, the adequacy of habitat offsetting measures, and the need for security and navigability of the river during construction. Requests include increasing offsetting to 5%, confirming security measures, and ensuring access for hunters and fishers.